Mozilla

Faster Vue.js Execution in Firefox

Firefox performance on Vue.js has improved significantly throughout the year. Most recently, we sped up reactivity with Proxy optimizations.

Autogenerating Rust-JS bindings with UniFFI

This blog post will walk through how we developed UniFFI: a Rust library for auto-generating foreign language bindings.

So you want to build your own open source ChatGPT-style chatbot…

A small team within Mozilla’s innovation group recently undertook a hackathon to build a trustworthy internal chatbot prototype.

Letting users block injected third-party DLLs in Firefox

Users can now block poorly behaving third-party DLLs in Firefox to improve stability and performance.

Mozilla Launches Responsible AI Challenge

We are relaunching our Mozilla Builders program with the Responsible AI Challenge. At Mozilla, we believe in AI and its powers.

Announcing Interop 2023

Interop 2022 showed significant improvements in the interoperability of multiple platform features. We're pleased to announce Interop 2023.

Interop 2022: Outcomes

Last March we announced the Interop 2022 project. Now that it's 2023, it's a good time to reflect on how the first year of Interop has gone.

How the Mozilla Community helps shape our products

Our awesome community is there every step of the way to support and contribute to our products. Working together to build a better internet.

Improving Firefox stability with this one weird trick

Poorly behaving web pages and apps are no longer capable of crashing the browser by exhausting memory, thanks to a simple trick.

Revamp of MDN Web Docs Contribution Docs

The MDN Web Docs team recently undertook a project to revamp and reorganize the “Contribution Docs”. The docs are an essential resource.

Improving Firefox responsiveness on macOS

If you're running Firefox on macOS you might have noticed that its responsiveness has improved significantly in version 103.

The 100% Markdown Expedition

In this post, we’ll describe why we decided to migrate to Markdown, and the steps you can take that will help us on our mission.

Merging two GitHub repositories without losing commit history

How do you merge two Git repositories without losing history? This post will take you through the step by step process.

Neural Machine Translation Engine for Firefox Translations add-on

We breakdown the technical challenges around the development of the translation engine and how we solved them to build a Firefox Translations add-on.

The JavaScript Specification has a New License

As part of our work to ensure a free and open web, we've been working with Ecma International to write a License inspired by the W3C Document.

Fuzzing rust-minidump for Embarrassment and Crashes – Part 2

For the last year, we've been working on the development of rust-minidump. The final part in this series takes you through fuzzing rust-minidump.

Hacks Decoded: Bikes and Boomboxes with Samuel Aboagye

Samuel Aboagye is 17 years old. He has crafted inventions such as a solar-powered bike and a Bluetooth speaker, both using recycled materials.

Everything Is Broken: Shipping rust-minidump at Mozilla – Part 1

We've been working on the development of rust-minidump. The first in this two-part series explains what minidumps are and how we made rust-minidump.

Training efficient neural network models for Firefox Translations

The Firefox Translations web extension utilizes proceedings of project Bergamot and brings local translations to Firefox.

Improved Process Isolation in Firefox 100

Firefox uses a multi-process model for additional security and stability while browsing. Web Content is rendered in separate processes.

Common Voice dataset tops 20,000 hours

The latest Common Voice dataset has achieved more than 20,000 hours of open-source speech data that anyone, anywhere can use.

MDN Plus now available in more countries

We are very glad to announce today that it is now possible for MDN users around the globe to create an MDN Plus free account.

Adopting users’ design feedback

On March 1st, 2022, MDN Web Docs released a new design and a new brand identity. Here is a summary of how we're addressing the feedback.

Mozilla partners with the Center for Humane Technology

We’re pleased to announce that we have partnered with the Center for Humane Tech, a nonprofit org that reimagines the digital infrastructure.

Performance Tool in Firefox DevTools Reloaded

In Firefox 98, we’re shipping a new version of the existing Performance panel. This panel is now based on the Firefox profiler tool.

Introducing MDN Plus: Make MDN your own

Today, we are launching MDN Plus, our first step to providing a personalized and more powerful experience while continuing to invest in our always free and open webdocs.

Mozilla and Open Web Docs working together on MDN

With the upcoming launch of MDN Plus, we believe it’s a good time to talk about how our two organizations work together.

Announcing Interop 2022

Interop 2022 is a cross-browser initiative to find and address the most important interoperability pain points on the web platform.

A new year, a new MDN

If you’ve accessed the MDN website today, you probably noticed that it looks quite different.

Version 100 in Chrome and Firefox

Chrome and Firefox will reach version 100 in a couple of months. Let's work together on fixing User Agent detection issues.

Improving the Storage Access API in Firefox

Before we roll out State Partitioning for all Firefox users, we intend to make a few improvements to the Storage Access API.

Retrospective and Technical Details on the recent Firefox Outage

On January 13th 2022, Firefox became unusable for close to two hours for users worldwide. This post highlights the complex series of events and circumstances that, together, triggered a bug deep in the networking code of Firefox.

Hacks Decoded: Adewale Adetona

Adetona Adewale Akeem is the co-founder of Menopays. We chatted with him about founding Menopays and the impact of tech solutions developed in Nigeria.

Contributing to MDN: Meet the Contributors

We reached out to four MDN contributors to talk about how and why they started contributing and what advice they have for new contributors.

Hacks Decoded: Sara Soueidan, Award-Winning UI Design Engineer and Author

We chatted with Sara Soueidan about front-end web development, the importance of design and her appreciation of birds.

WebAssembly and Back Again: Fine-Grained Sandboxing in Firefox 95

In Firefox 95, we're shipping a sandboxing technology called RLBox — developed with researchers at UC San Diego and the University of Texas

Hacks Decoded: Seyi Akiwowo, Founder of Glitch

We spoke with Seyi Akiwowo to learn about what drives her, why she does what she does and what she’d be doing if not battling online trolls.

Hacks Decoded: Thomas Park, Founder of Codepip

Welcome to our Hacks: Decoded Interview series! We spoke with Thomas over email about coding, his favorite apps and his past life at Mozilla.

Lots to see in Firefox 93!

Firefox 93 comes with lots of lovely updates including AVIF image format support, filling of XFA-based forms in its PDF viewer and protection.

Implementing form filling and accessibility in the Firefox PDF viewer

We decided it was time to reinvest in the PDF viewer (PDF.js) and support filling PDF forms within Firefox to make our users' lives easier.

Control your data for good with Rally

Mozilla Rally puts you in control of your data while building a better Internet and better society. With your help, we can create a safer web.

Tab Unloading in Firefox 93

Firefox will monitor available system memory and, should it become that a crash is imminent, Firefox will respond by unloading memory-heavy.

MDN Web Docs at Write the Docs Prague 2021

The MDN Web Docs team is pleased to sponsor Write the Docs Prague 2021, which is being held remotely this year.

Time for a review of Firefox 92

Release time comes around so quick! This month we have a few CSS updates, along with the new Object.hasOwn() static method for JavaScript.

Spring cleaning MDN: Part 2

We have ~11k active pages on MDN, so keeping them up to date is a big task and we feel our focus should be there.

Hopping on Firefox 91

August is already here, which means so is Firefox 91! For developers Firefox 91 supports the Visual Viewport API and Intl.DateTimeFormat object additions.

How MDN’s autocomplete search works

Autocomplete search added to MDN Web Docs allows you to quickly jump to the document you're looking for by typing parts of the document title

Spring Cleaning MDN: Part 1

We made some big platform changes at the end of 2020. It’s given us a great opportunity to clear out the cupboards and closets.

Getting lively with Firefox 90

This release we see nice JavaScript additions, including private fields and methods for classes, String and TypedArray global objects.

Implementing Private Fields for JavaScript

Private fields are a language feature being added to the JavaScript language through the TC39 proposal process.

Looking fine with Firefox 89

Firefox 89 has smartened up and brings with it a more minimalist interface. We get some great features including a force-colors feature.

Improving Firefox stability on Linux

A year ago at Mozilla we started to improve Firefox stability on Linux. This effort quickly became an example of good synergies between FOSS.

Introducing Firefox’s new Site Isolation Security Architecture

With Site Isolation enabled on Firefox for Desktop, Mozilla takes its security guarantees to the next level.

Pyodide Spin Out and 0.17 Release

We are happy to announce that Pyodide has become an independent and community-driven project and are pleased to announce the 0.17 release.

Never too late for Firefox 88

April is upon us, and we have a most timely release for you — Firefox 88. In this release you will find a bunch of nice CSS additions.

QUIC and HTTP/3 Support now in Firefox Nightly and Beta

Support for QUIC and HTTP/3 is now enabled by default in Firefox Nightly and Firefox Beta. HTTP/3 will be available by the end of May.

Eliminating Data Races in Firefox – A Technical Report

We successfully deployed ThreadSanitizer in the Firefox project to eliminate data races in our remaining C/C++ components. In the process, we found several impactful bugs and can safely say that data races are often underestimated in terms of their impact on program correctness.

A web testing deep dive: The MDN web testing report

This year we did a deep dive into web testing, and we are delighted to be able to announce the publication of this follow-on work.

MDN localization in March — Tier 1 locales unfrozen, and future plans

Since we last talked about MDN localization, a lot of progress has been made. We've finally achieved our goal of unfreezing Tier 1 locales.

In March, we see Firefox 87

Nearing the end of March now, and we have a new version of Firefox ready to deliver some interesting new features to your door.

How MDN’s site-search works

Periodically, the whole of MDN is built, by our Node code , in a GitHub Action. Results' sort-order is determined by match and "popularity"

Here’s what’s happening with the Firefox Nightly logo

Long story short, the fox is here to stay and for our Nightly users we’re bringing back a special version of an older logo, as a treat.

A Fabulous February Firefox — 86!

Looking into the near distance, we can see the end of February. To keep you engaged until then, we’d like to introduce you to Firefox 86.

Introducing State Partitioning

State Partitioning is the new privacy feature called Total Cookie Protection, which will be available in ETP Strict Mode in Firefox 86.

MDN localization update, February 2021

An update on MDN Web Docs’ localization strategy, our broad strategy for moving forward with allowing translation edits on MDN again.

Browser fuzzing at Mozilla

Mozilla has been fuzzing Firefox for a while. It has proven to be one of the most efficient ways to identify quality and security issues.

January brings us Firefox 85

To wrap up January, we are proud to bring you the release of Firefox 85. In this version we complete removal of Flash support from Firefox.

Welcoming Open Web Docs to the MDN family

We’re happy and proud to announce Open Web Docs, to support a community of technical writers that is open and inclusive for all.

Analyzing Bugzilla Testcases with Bugmon

To reduce the delay in getting bugs fixed, we developed Bugmon; a tool that automates basic triage tasks for bugs directly in Bugzilla.

Porting Firefox to Apple Silicon

The release of Apple Silicon based Macs at the end of last year generated a flurry of news and some surprises at the machine’s performance.

Improving Cross-Browser Testing, Part 2: New Automation Features in Firefox Nightly

we have shipped an experimental implementation of parts of CDP in Firefox Nightly, specifically targeting the use cases of end-to-end testing using Google’s Puppeteer, and the CDP-based features of Selenium 4.

Improving Cross-Browser Testing, Part 1: Web Application Testing Today

With our commitment to building a better Internet, we want to provide web developers the tools they need to build great web experiences.

2020 MDN Web Developer Needs Assessment now available

The 2020 MDN Web Developer Needs Assessment (DNA) report is now available! This post takes you through what we’ve accomplished in 2020.

And now for … Firefox 84

As December ushers in the final curtain for this rather eventful year, there is time left for one more Firefox version to be given its wings.

Welcome Yari: MDN Web Docs has a new platform

After several intense months of work on such a significant change, the MDN Web Docs’ new platform (codenamed Yari) is finally launched!

An update on MDN Web Docs’ localization strategy

In our previous post — MDN Web Docs evolves! Lowdown on the upcoming new platform — we talked about many aspects of the new MDN Web Docs platform that we’re ...

Flying the Nest: WebThings Gateway 1.0

We are excited to announce the release of WebThings Gateway 1.0 and a new home for the WebThings platform.

Foundations for the Future

Mozilla is pleased to see Servo, which began as a research effort in 2012, open new doors that can lead it to broader benefits for users.

Firefox 83 is upon us

In this release we’ve got a few nice additions: Conical CSS gradients, overflow debugging in the Developer Tools, enabling of WebRender.

Warp: Improved JS performance in Firefox 83

We have enabled Warp, a significant update to SpiderMonkey, by default in Firefox 83. SpiderMonkey, the JavaScript engine used in the Firefox

MDN Web Docs evolves! Lowdown on the upcoming new platform

The time has come for Kuma — the platform that powers MDN Web Docs — to evolve. “What does a Kuma evolve into? A KumaMaMa?”

MDN Web Docs: Editorial strategy and community participation

We’ve made a lot of progress on moving forward with MDN Web Docs and we wanted to share where we are headed in the short- to mid-term.

Coming through with Firefox 82

We are pushing Firefox 82 out the door, with enabled support for the Media Session API, new CSS pseudo-selector behaviours and closed security loopholes.

A New Backend for Cranelift, Part 1: Instruction Selection

This post will describe my recent work on Cranelift as part of my day job at Mozilla. In this post, I will set some context and describe the instruction selection problem. In particular, I’ll talk about a revamp to the instruction selector and backend framework in general that we’ve been working on.

To Eleventy and Beyond

We launched Firefox Extension Workshop, using the Ruby-based static site generator Jekyll, and then realized that we needed to find an alternative and port the site.

An Update on MDN Web Docs

Last week, Mozilla announced some general changes in our investments and we would like to outline how they will impact our MDN platform efforts moving forward. It hurts to make ...

js13kGames 2020: A lean coding challenge with WebXR and Web Monetization

Announcing the return of the annual month-long competition for HTML5 game developers. For js13kGames contestants, the file size limit for all entries is set to 13 kilobytes of code. That's ...

Changes to SameSite Cookie Behavior – A Call to Action for Web Developers

Browsers are changing the default value of the SameSite attribute for cookies from None to Lax. This will greatly improve security for users. However, some web sites may depend (even ...

Firefox 79: The safe return of shared memory, new tooling, and platform updates

Firefox 79 offers a new Promise method, more secure target=_blank links, logical assignment operators, tooling improvements for better JavaScript debugging, and many other updates of interest to web developers. In ...

MDN Web Docs: 15 years young

MDN Web Docs turns 15 years old! This celebratory article highlights fifteen big wins of the last five years. With initiatives like the browser compatibility data project, learning areas and ...

Safely reviving shared memory

At Mozilla, we want the web to be capable of running high-performance applications so that users and content authors can choose the safety, agency, and openness of the web platform. ...

Testing Firefox more efficiently with machine learning

A browser is an enormously complex piece of software, and it's always in development. About a year ago, we asked ourselves: how could we do better? Our CI relied heavily ...

Adding prefers-contrast to Firefox

When we talk about the contrast of a page, or contrast between web elements, we’re assessing how color choices impact readability. For visitors with low vision, web pages with low ...

Securing Gamepad API

As part of Mozilla’s ongoing commitment to improve the privacy and security of the web platform, over the next few months, we will be making some changes to the Gamepad ...

New in Firefox 78: DevTools improvements, new regex engine, and abundant web platform updates

Firefox 78 heads heads out the door with a new regex engine, updates to the ECMAScript Intl API, new CSS selectors, enhanced support for WebAssembly, some important WebExtensions API updates, ...

Mozilla WebThings Gateway Kit by OKdo

Mozilla WebThings Gateway is an open source software distribution focused on privacy, security, and interoperability. It provides a web-based user interface to monitor and control smart home devices over the ...

Welcoming Safari to the WebExtensions Community

Safari is adopting a web-based API for browser extensions similar to Firefox’s WebExtensions API making it easy to build once and port to multiple browsers. Developers

Compiler Compiler: A Twitch series about working on a JavaScript engine

Yulia Startsev, a JavaScript engineer on Firefox's SpiderMonkey team, introduces her new Twitch stream called Compiler Compiler. In the three opening interactive episodes, we get an inside look at how ...

Introducing the MDN Web Docs Front-end developer learning pathway

The MDN Web Docs Learning Area teaches fundamentals of modern web development, beginning with HTML, CSS, and JavaScript essentials. In feedback this year, readers asked for a more opinionated, structured ...

A New RegExp Engine in SpiderMonkey

Regular expressions – commonly known as RegExps – are a powerful and heavily used tool for manipulating strings in JavaScript. This post describes how we updated the RegExp engine in ...

New in Firefox 77: DevTool improvements and web platform updates

Firefox 77 is now available with a variety of developer tool updates and new web platform features. With your feedback, we've removed performance bottlenecks, resulting in faster, leaner JavaScript debugging. ...

Building FunctionTrace, a graphical Python profiler

Firefox Profiler is a powerful web-based performance analysis interface featuring call trees, stack charts, flame graphs, and more. All data filtering, zooming, slicing, and transformation actions are preserved in shareable ...

High Performance Web Audio with AudioWorklet in Firefox

Earlier this week, Audio Worklets landed in the release of Firefox 76. We’re ready to start bridging the gap between web audio and native. Developers can now leverage AudioWorklet to ...

Firefox 76: Audio worklets and other tricks

Firefox 76 delivers great new features for web platform support, such as Audio Worklets and Intl improvements, on the JavaScript side. Also, we’ve added a number of topnotch improvements to ...

Fuzzing Firefox with WebIDL

Fuzzing, or fuzz testing, is an automated approach for testing the safety and stability of software. For the past 3 years, the Firefox fuzzing team has been developing a new ...

A Taste of WebGPU in Firefox

WebGPU is an emerging API, designed from the ground up within the W3C, to provide access to the graphics and computing capabilities of hardware on the web.

Engineering code quality in the Firefox browser: A look at our tools and challenges

Here's an insider's look at Firefox's code quality toolchain that's been designed to manage the ongoing development and monthly releases of our desktop browser. This post explores the architecture, challenges, ...

Firefox 75: Ambitions for April

Firefox 75 is chock full of handy new dev tooling: instant evaluation in the web console, event breakpoints for WebSockets, and more. New web platform features include HTML lazy loading ...

Twitter Direct Message Caching and Firefox

Distinguished engineer Martin Thomson explains how this problem occurred, the implications for people who might be affected, and how problems of this nature might be avoided in future. To get ...

Innovating on Web Monetization: Coil and Firefox Reality

An in-depth introduction to web monetization with Coil. Coil is a payments platform that doesn't really on advertising or personal data collection to support digital content creators directly. Firefox Reality ...

Learn web technology at “sofa school”

Here are some web development learning resources for kids of all ages. All you need is a web browser. This collection looks at social VR experiences using Hubs and Spoke, ...

Security means more with Firefox 74

The release of Firefox 74 is focused on security enhancements: Feature Policy, the Cross-Origin-Resource-Policy header, and removal of TLS 1.0/1.1 support. We’ve also got some new CSS text property features, ...

Future-proofing Firefox’s JavaScript Debugger Implementation

Optimizing the integration of Firefox Developer Tools with the SpiderMonkey JavaScript engine has resulted in many benefits, including the new asynchronous call stack tracking now available in Firefox Developer Edition. ...

Securing Firefox with WebAssembly

Protecting the security and privacy of individuals is a central tenet of Mozilla’s mission. While we continue to make extensive use of both sandboxing and Rust in Firefox to address ...

WebThings Gateway Goes Global

A walkthrough of what's new in the WebThings Gateway 0.11 release, which lets you build your own web things with the latest WebThings Framework libraries. The biggest change in this ...

Firefox 73 is upon us

Today we’ve released Firefox 73, with useful additions that include CSS and JavaScript updates, and numerous DevTools improvements. We’ve added to CSS logical properties, pushed performance forward in the Console ...

It’s the Boot for TLS 1.0 and TLS 1.1

The Transport Layer Security (TLS) protocol is the de facto means for establishing security on the Web. The newest version, TLS 1.3, improves efficiency and remedies the flaws and weaknesses ...

The Mozilla Developer Roadshow: Asia Tour Retrospective and 2020 Plans

November 2019 was a busy month for the Mozilla Developer Roadshow, with stops in five Asian cities —Tokyo, Seoul, Taipei, Singapore, and Bangkok. Today, we’re releasing a playlist of the ...

How we built Picture-in-Picture in Firefox Desktop with more control over video

A behind-the-scenes look at the evolution of the Picture-in-Picture player for the Firefox Desktop browser. This feature is now available for MacOS, Linux and Windows users. From the beginning, it's ...

Firefox 72 — our first song of 2020

2020 is upon us, folks. We'd like to wish everyone reading this a happy new year, wherever you are. As you take your first steps of the new year, figuring out what your next move is, you may find it comforting to know that there's a new Firefox release to try out! Version 72 to be exact.

Presenting the MDN Web Developer Needs Assessment ( Web DNA) Report

The first annual MDN Developer Needs Assessment aims to represent the voices of developers and designers working on the web. We've analyzed the data provided by more than 28,000 completed ...

Mozilla Hacks’ 10 most-read posts of 2019

Mozilla Hacks covered plenty of interesting territory in 2019. Our most popular posts introduced experiments and special projects, and described the evolution of groundbreaking platform technologies like WebAssembly and WASI. ...

Debugging Variables With Watchpoints in Firefox 72

Have you ever wanted to know where properties on objects are read or set in your code, without having to manually add breakpoints or log statements? Watchpoints are a type ...

DeepSpeech 0.6: Mozilla’s Speech-to-Text Engine Gets Fast, Lean, and Ubiquitous

The Machine Learning team at Mozilla continues work on DeepSpeech, an automatic speech recognition (ASR) engine which aims to make speech recognition technology and trained models openly available to developers. ...

Using WebAssembly from .NET with Wasmtime

How to use Wasmtime in a .NET application to load and execute WebAssembly code.

Firefox 71: A winter arrival

Please welcome Firefox 71 to the stage! This time around, we have a plethora of new developer tools features including the web socket message inspector, console multi-line editor mode, log ...

Firefox 71: A year-end arrival

Please welcome Firefox 71 to the stage! This time around, we have a plethora of new developer tools features including the web socket message inspector, console multi-line editor mode, log ...

Multi-Value All The Wasm!

Multi-value is a proposed extension to core WebAssembly that enables functions to return many values, among other things. It is also a prerequisite for Wasm interface types. Nick Fitzgerald has ...

Multiple-column Layout and column-span in Firefox 71

Firefox 71 adds the column-span property from Multiple-column Layout. In this post Rachel Andrew takes a look at the implementation.

Creating UI Extensions for WebThings Gateway

Version 0.10 of Mozilla’s WebThings Gateway brings support for extension-type add-ons. Released last week, this powerful new capability lets developers modify the user interface (UI) to their liking with JavaScript ...

Thermostats, Locks and Extension Add-ons – WebThings Gateway 0.10

Today we are releasing WebThings Gateway 0.10. This new release comes with support for thermostats and smart locks, as well as an updated add-ons system including extension add-ons, which enable ...

Upcoming notification permission changes in Firefox 72

Earlier this year we decided to reduce the amount of unsolicited notification permission prompts people receive as they move around the web using the Firefox browser. This is an intrinsic ...

Announcing the Bytecode Alliance: Building a secure by default, composable future for WebAssembly

Lin Clark introduces the Bytecode Alliance, and uses Code Cartoon illustrations to share their vision of a WebAssembly ecosystem that is secure by default, fixing cracks in today’s software foundations. ...

Auditing For Accessibility Problems With Firefox Developer Tools

In Firefox 70, the Accessibility Inspector has become an auditing facility to help identify and fix many common mistakes and practices that reduce site accessibility. In this post, Marco Zehe ...

From js13kGames to MozFest Arcade: A game dev Web Monetization story

This is a case study in the making: how js13kGames, an online “code golf” competition for web game developers, tried out Web Monetization this year. And ended up at the ...

The two-value syntax of the CSS Display property

The display CSS property is how we change the formatting context of an element and its children. One of the first things you will learn about CSS is that some ...

Firefox 70 — a bountiful release for all

Firefox 70 is released today, and includes great new features such as secure password generation with Lockwise and the new Firefox Privacy Protection Report, as well as cool additions for ...

Quickly Alter Typography with Firefox Font Editor

Have you ever landed on a web page and wondered what fonts are being used? Have you asked yourself where those fonts come from or why a particular font isn't ...

Faster Layouts with CSS Grid (and Subgrid!)

CSS Grid has been available in most major browsers since early 2017, and it makes web layout more powerful than ever before. But complex-looking new syntax (line-names! grid-areas! minmax! fit-content! ...

Developing cross-browser extensions with web-ext 3.2.0

The web-ext tool was created at Mozilla to help you build browser extensions faster and more easily. Although our first launch focused on support for the desktop Firefox browser, followed ...

Firefox’s New WebSocket Inspector

The Firefox DevTools team and our contributors were hard at work over the summer, getting Firefox 70 jam-packed with improvements. We are especially excited about our new WebSocket inspection feature. ...

The Mozilla Developer Roadshow Talks: Firefox, WebAssembly, CSS, WebXR and More

The Mozilla Developer Roadshow program launched in 2017 with the goal of bringing expert speakers and web technology updates to local communities through free events and partnerships. Check out the ...

Why is CSS so Weird?

CSS is the design language of the web — one of three core web languages — but it also seems to be the most contentious and often perplexing. It's too ...

Video Shorts from Mozilla Developer

We’re excited to launch a new resource for people who build the web – with short videos, articles, demos, and tools that teach web technologies and standards, browser tools, compatibility, and more. No matter our experience levels and job descriptions, we’re all working together towards the future health of the web – and Mozilla is here to help.

WebHint in Firefox DevTools: Improve Compatibility, Accessibility and more

Creating experiences that look and work great across different browsers is one of the biggest challenges on the web. It can also be the most rewarding part, as it gets ...

Why is CSS so Weird?

CSS is the design language of the web — one of three core web languages — but it also seems to be the most contentious and often perplexing. It's too ...

Exploring Collaboration and Communication with Mozilla Hubs

As we look at advancements in mixed reality like the WebXR API, we are able to explore ways to feel more present with others through technology. Hubs by Mozilla is ...

Moving Firefox to a faster 4-week release cycle

Building and releasing a browser is complicated and involves many players. To optimize the process, and make it more reliable for all users, over the years we’ve developed a phased ...

Caniuse and MDN compatibility data collaboration

Today we’re announcing the integration of MDN’s compat data into the caniuse website. Together, we’re bringing even more web compatibility information into the hands of web developers.

Debugging TypeScript in Firefox DevTools

Firefox Debugger has evolved into a fast and reliable tool chain over the past several months and it’s now supporting many cool features. Though it's primarily used to debug JavaScript, ...

Debugging WebAssembly Outside of the Browser

WebAssembly has begun to establish itself outside of the browser via dedicated runtimes like Mozilla’s Wasmtime and Fastly’s Lucet. While the promise of a new, universal format for programs is ...

Firefox 69 — a tale of Resize Observer, microtasks, CSS, and DevTools

For our latest excellent adventure, we’ve gone and cooked up a new Firefox release. Version 69 features a number of great new additions including JavaScript public instance fields, the Resize ...

The Baseline Interpreter: a faster JS interpreter in Firefox 70

Modern web applications load and execute a lot more JavaScript code than they did just a few years ago. While JIT (just-in-time) compilers have been very successful in making JavaScript ...

WebAssembly Interface Types: Interoperate with All the Things!

People are excited about running WebAssembly outside the browser. People are also excited about running WebAssembly from languages like Python, Ruby, and Rust. Lin Clark's Code Cartoons are back, illustrating ...

Using WebThings Gateway notifications as a warning system for your home

The WebThings Gateway 0.9 release lets you set up a number of different notification mechanisms including emails, apps, and text messages. In this post James Hobin shows how to set ...

New CSS Features in Firefox 68

Firefox 68 landed earlier this month with a bunch of CSS additions and changes. In this blog post Rachel Andrew takes a look at some of the things you can ...

WebThings Gateway for Wireless Routers

The Mozilla IoT team has been working on evolving WebThings Gateway into a full software distribution for consumer wireless routers. Today, with the 0.9 release, we’re happy to announce the ...

MDN’s First Annual Web Developer & Designer Survey

Today we are launching our first annual MDN Developer & Designer Needs Survey. Web developers and designers, we urge you to participate! This is your opportunity to tell us about ...

Add-Ons Outage Post-Mortem Result

We've been conducting an ongoing post-mortem on the add-ons outage that occurred earlier this year. There was a lot more digging to do than we expected. In addition to this ...

Testing Picture-in-Picture for videos in Firefox 69 Beta and Developer Edition

Have you ever needed to leaf through a recipe while also watching a cooking video? Or perhaps you wanted to watch a recording of a lecture while also looking at the course slides. Or maybe you wanted to watch somebody stream themselves playing videogames while you work.

Firefox 68: BigInts, Contrast Checks, and the QuantumBar

Firefox 68 is available today, sporting support for big integers, whole-page contrast checks checks for accessibility, and a completely new implementation of a core Firefox feature: the ever-awesome URL bar. ...

GeckoView in 2019

Introducing the initial release of Firefox Preview (GitHub), an entire browser built from the ground up with GeckoView and Mozilla Android Components. Firefox Preview is our platform for building, testing, ...

How accessibility trees inform assistive tech

The web was designed with built-in features to make accessibility possible; these have been part of the platform pretty much from the beginning. In recent times, inspectable accessibility trees have ...

View Source 5 comes to Amsterdam

Mozilla’s View Source Conference is back! This year we're in Amsterdam, September 30 – October 1, 2019. Tickets are available now. We’ve shifted our focus to take a deeper look ...

CSS Scroll Snap Updated in Firefox 68

The CSS Scroll Snap specification gives us a way in CSS to snap between different elements in a page or scrolling component. In this post, Rachel Andrew explains how scroll ...

CSS Grid Level 2 – subgrid is coming to Firefox

The subgrid feature which is part of Level 2 of the CSS Grid Specification is not yet shipping in any browser, but is now available for testing in Firefox Nightly. ...

Indicating focus to improve accessibility

Focus indicators make the difference between day and night for people who rely on them. Focus is something that happens between the interactive elements on a page. In this post ...

JavaScript and evidence-based language design

In what ways can empirical evidence be used in the design of a language like JavaScript? What kind of impact would user data, and a more direct connection to developers give us?

Firefox brings you smooth video playback with the world’s fastest AV1 decoder

With this week's release of Firefox 67, the new high performance royalty-free AV1 video decoder dav1d is now enabled by default on all desktop platforms (Windows, OSX and Linux) for ...

Firefox 67: Dark Mode CSS, WebRender, and more

Firefox 67 is now available in general release, bringing a faster and better JavaScript debugger, support for CSS prefers-color-scheme queries, and the initial debut of WebRender in stable Firefox. Dan ...

Faster smarter JavaScript debugging in Firefox DevTools

Script debugging is one of the most powerful and complex productivity features in the web developer toolbox. Done right, it empowers developers to fix bugs quickly and efficiently. The DevTools ...

Empowering User Privacy and Decentralizing IoT with Mozilla WebThings

In designing Mozilla WebThings, we have consciously insulated users from servers that could harvest their data, including our own Mozilla servers, by offering an interoperable, decentralized IoT solution. Learn about ...

TLS 1.0 and 1.1 Removal Update

Enable support for TLS 1.2 today!

Technical Details on the Recent Firefox Add-on Outage

Recently, Firefox had an incident in which most add-ons stopped working. This was due to an error on our end: we let one of the certificates used to sign add-ons ...

Owning it: browser compatibility data and open source governance

What does it mean to “own” an open-source project? With the browser-compat-data project (“BCD”), the MDN (Mozilla Developer Network) community and I recently had the opportunity to find out.

Introducing Mozilla WebThings

Mozilla WebThings is an open platform for monitoring and controlling devices over the web.

Fluent 1.0: a localization system for natural-sounding translations

Fluent is a family of localization specifications, implementations and good practices developed by Mozilla. With Fluent, translators can create expressive translations that sound great in their language. Today we’re announcing ...

Pyodide: Bringing the scientific Python stack to the browser

Pyodide is an experimental project from Mozilla to create a full Python data science stack that runs entirely in the browser. We think it’s worthwhile to work on moving the ...

Developer Roadshow 2019 returns with VR, IoT and all things web

Mozilla Developer Roadshow is a meetup-style, Mozilla-focused event series for people who build the web. In 2017, the Roadshow reached more than 50 cities around the world sharing highlights of ...

Teaching machines to triage Firefox bugs

To help get bugs in front of the right Firefox engineers quickly, we developed BugBug, a machine learning tool that automatically assigns a product and component for each new untriaged ...

Sharpen your WebVR skills with experiments from Glitch and Mozilla

Earlier this year, we partnered with Glitch.com on a starter kit that teaches the fundamentals of WebVR using A-Frame. Today, we introduce a week of WebVR experiments that build on ...

Crossing the Rust FFI frontier with Protocol Buffers

The Firefox Application Services engineering team made the decision to use Rust to build cross-platform components for Firefox Sync, powering Firefox Accounts across many devices. They are implementing core business ...

A Real-Time Wideband Neural Vocoder at 1.6 kb/s Using LPCNet

This is an update on the LPCNet project, an efficient neural speech synthesizer from Mozilla’s Emerging Technologies group. LPCNet combines signal processing and deep learning to improve the efficiency of ...

Scroll Anchoring in Firefox 66

Firefox 66 was released last week with a new feature called scroll anchoring, based on a new CSS specification. Scroll anchoring works to anchor the user to the content they’re ...

Standardizing WASI: A system interface to run WebAssembly outside the web

WebAssembly is an assembly language for a conceptual machine, not a physical one. This is why it can be run across a variety of different machine architectures. WebAssembly needs a ...

Firefox 66: The Sound of Silence

Firefox 66 is out, and brings with it a host of great new features like screen sharing, scroll anchoring, autoplay blocking for audible media, and initial support for the Touch ...

A Homepage for the JavaScript Specification

Screenshot of the TC39 website     Ecma TC39, the JavaScript Standards Committee, is proud to announce that we have shipped a website for following updates to the JavaScript specification. ...

Fast, Bump-Allocated Virtual DOMs with Rust and Wasm

Dodrio is a new virtual DOM library that is designed to leverage the strengths of both Wasm’s linear memory and Rust’s low-level control by making extensive use of fast bump ...

Iodide: an experimental tool for scientific communication and exploration on the web

Meet Iodide, an experimental open source tool to help scientists write beautiful interactive documents using web technologies, all within a browser-based iterative workflow that will be familiar to many scientists.

Real virtuality: connecting real things to virtual reality using web technologies

WebXR meets the Web of Things when two developers build a prototype that applies 3D visualisation to power an IoT interface. In this post they demonstrate how open, accessible web ...

Implications of Rewriting a Browser Component in Rust

Since our first release in 2002, there have been 69 security bugs in Firefox’s style component. If we'd had a time machine and could have written this component in Rust from the start, 51% wouldn't have happened. That said, Rust is not foolproof. Developers still need to be aware of correctness bugs and data leakage attacks.

Announcing a New Management Structure for Ecma TC39

In 2019, Ecma’s TC39 (the standardizing body behind JavaScript/ECMAScript) will be trying something new. The committee has grown in the last few years, and the requirements of running the meeting have grown. To give you an idea of the scale, between 40 and 60 delegates meet 6 times a year to discuss proposed changes to the ECMAScript specification.

Web Design Survey Findings and Next Steps

In November, I wrote about my team’s work on experimental new web design tools and introduced a survey to rank the challenges of web design and development. The insights you ...

Fearless Security: Thread Safety

Multithreading allows programs to do more faster, but adds synchronization bugs and attacks. From a security standpoint, why do we care about thread safety?

Anyone can create a virtual reality experience with this new WebVR starter kit from Mozilla and Glitch

Building a virtual reality experience may seem daunting, but it really isn’t. WebVR and frameworks like A-Frame make it really easy to get started. This is why we worked with Glitch to create a WebVR starter kit. It is a free, 5-part video course with interactive code examples that will teach you the fundamentals of WebVR using A-Frame. Our hope is that this starter kit will encourage anyone who has been on the fence about creating virtual reality experiences to dive in and get started.

Refactoring MDN macros with async, await, and Object.freeze()

We completed a major refactor of the MDN macro rendering code using JavaScript Promises, async, await, Object.create() and Object.freeze().

Firefox 66 to block automatically playing audible video and audio

Unsolicited volume can be a great source of distraction and frustration for users of the web. So we are making changes to how Firefox handles playing media with sound and ...

New in Firefox DevTools 65

We just released Firefox 65 with a number of new developer features that make it even easier for you to create, inspect and debug the web. Among all the features ...

Firefox 65: WebP support, Flexbox Inspector, new tooling & platform updates

Firefox 65 ships today with some notable Firefox Devtools updates, including the release of the CSS Flexbox Inspector, a new changes panel, and more. We're shipping CSS platform improvements and ...

Cameras, Sensors & What’s Next for Mozilla’s Things Gateway

With the release of Things Gateway 0.7, Mozilla's IoT team announces experimental support for IP cameras, along with support for a wider range of sensors that track temperature, leaks, and ...

Fearless Security: Memory Safety

Memory safety violations can cause programs to crash unexpectedly and can be exploited to alter intended behavior--languages can manage this multiple ways

How to make VR with the web, a new video series

Introducing a new 7-part video series with Josh Marinacci: How to make a virtual reality project in your browser with three.js & WebVR. These short tutorials show how to create ...

MDN Changelog – Looking back at 2018

John Whitlock highlights MDN's engineering accomplishments of 2018 - including major advances in converting MDN's documentation to structured data via the Browser Compat Data project, and in extending the Interactive ...

Augmented Reality and the Browser — An App Experiment

hacks.mozilla.org

Designing the Flexbox Inspector

CSS Flexbox is an increasingly popular layout model that helps in building robust dynamic page layouts. However, it has a big learning curve! The new Flexbox Inspector, created by Firefox ...

Mozilla Hacks’ 10 most-read posts of 2018

Our top posts this year were read by hundreds of thousands of developers and ranged across a variety of categories - including JavaScript and WebAssembly, CSS, the Web of Things, ...

MDN Changelog for November 2018

MDN wraps up a year of hard work by shipping monthly MDN payments, converting from Font Awesome to SVG, adding browser names to compatibility tables, and growing the development team. ...

Firefox 64 Released

The year's last release of Firefox bundles together goodies for all, including multi-tab management in the interface, new CSS features, devtools improvements, better privacy protections, add-ons updates, and much, much ...

Rust 2018 is here… but what is it?

Starting today, the Rust 2018 edition is in its first release. With this edition, we’ve focused on making Rust developers as productive as they can be. Most of the language ...

LPCNet: DSP-Boosted Neural Speech Synthesis

LPCNet is a new project out of Mozilla's Emerging Technologies group — an efficient neural speech synthesiser with reduced complexity over some of its predecessors. Neural speech synthesis models like ...

Decentralizing Social Interactions with ActivityPub

ActivityPub is a W3C standard protocol that describes ways for different social network sites (loosely defined) to talk to and interact with one another. ActivityPub aims to do for social ...

The Power of Web Components

Web Components comprises a set of standards that enable user-defined HTML elements. These elements can go in all the same places as traditional HTML. Despite the long standardization process, the ...

New & Experimental Web Design Tools: Feedback Requested

We’re currently hard at work on some new tools for web designers: a comprehensive Flexbox Inspector as well as CSS change-tracking. Tell us about your biggest CSS and web design ...

Private by Design: How we built Firefox Sync

Firefox Sync by default protects all your synced data so Mozilla can’t read it. We built Sync this way because we put user privacy first. How it works is...

Performance Updates and Hosting Moves: MDN Changelog for October 2018

This month's changelog, from the hard-working engineering team that builds and maintains the MDN Web Docs site, covers performance improvements and experiments, infrastructure updates, as well as countless tweaks and ...

Into the Depths: The Technical Details Behind AV1

AV1, the next generation royalty-free video codec from the Alliance for Open Media leapfrogs the performance of VP9 and HEVC. The AV1 format is and will always be royalty-free with ...

Cross-language Performance Profile Exploration with speedscope

speedscope is a fast, interactive, web-based viewer for large performance profiles, inspired by the performance panel of Chrome developer tools and by Brendan Gregg’s FlameGraphs. Jamie Wong built speedscope to ...

Testing Privacy-Preserving Telemetry with Prio

Building a browser is hard; building a good browser inevitably requires gathering a lot of data to make sure that things that work in the lab works in the field. ...

Dweb: Identity for the Decentralized Web with IndieAuth

IndieAuth is a decentralized login protocol that enables users of your software to log in to other apps. It's an extension to OAuth 2.0 that lets any website to become ...

Firefox 63 – Tricks and Treats!

Firefox 63 comes with some long-awaited treats: an implementation of web components, including custom elements and the shadow DOM. Potch also covers the Fonts Editor, the associated font panel in ...

WebAssembly’s post-MVP future: A cartoon skill tree

People have a misconception—they think that the WebAssembly that landed in browsers back in 2017—is the final version. In fact, we still have many use cases to unlock, from heavy-weight ...

Introducing Opus 1.3

Opus is a totally open, royalty-free, audio codec that can be used for all audio applications, from music streaming and storage to high-quality video-conferencing and VoIP. This 1.3 release brings ...

Dweb: Decentralised, Real-Time, Interoperable Communication with Matrix

Matrix is an open standard for interoperable, decentralised, real-time communication over the Internet. It provides a standard HTTP API for publishing and subscribing to real-time data in specified channels, so ...

Show your support for Firefox with new badges

If you use Firefox and want to show your support, we've made a collection of badges you can add to your website. Whether you're passionate about Mozilla's mission, or just ...

Payments, accessibility, and dead macros: MDN Changelog for September 2018

Changes and updates to the code, data, and tools that support MDN Web Docs. In September, the team launched MDN payments, improved MDN’s accessibility resources, and removed 15% of KumaScript ...

Home Monitoring with Things Gateway 0.6

The latest version of the Things Gateway rolling out today comes with new home monitoring features that let you directly monitor your home over the web, without a middleman. That ...

Calls between JavaScript and WebAssembly are finally fast 🎉

At Mozilla, we want WebAssembly to be as fast as it can be. This started with its design, which gives it great throughput. Then we improved load times with a ...

A New Way to Support MDN

MDN’s user base has grown exponentially in the last few years, so we are seeking support from our users to help accelerate content and platform development.

Hack on MDN: Better accessibility for MDN Web Docs

Making websites accessible to a wide range of users is a vital topic for creators on the web. Over a long weekend in late September, more than twenty people met ...

Performance-Tuning a WebVR Game

My goal: load a VR puzzle game in less than 10 seconds. The challenge: compressing and optimizing font, audio, and image files to hit my target.

Dweb: Creating Decentralized Organizations with Aragon

Aragon lets you build decentralized organizations with trust-less and transparent governance using Ethereum, IPFS, and the web.

Streaming RNNs in TensorFlow

How we built a streaming RNN model with TensorFlow and used it to make DeepSpeech leaner and faster.

MDN Changelog for August 2018

In August, the MDN content community reviewed and merged 85 Browser Compatibility Data pull requests, with help from volunteers.

Firefox Focus with GeckoView

Firefox Focus is a mobile app for ad-free, private browsing. Soon, Focus for Android will ship bundled with the Gecko engine for the first time.

Converting a WebGL application to WebVR

Research engineer Manish Goregaokar, who works on Servo and Rust, shares what he's learned and some of the code he wrote, while porting a WebGL application to WebVR.

New API to Bring Augmented Reality to the Web

The WebXR Device API has two goals that differentiate it from WebVR: support for new user inputs like voice and gestural navigation, and laying a foundation for augmented reality on ...

Firefox 62 – Tools Cool for School!

From the new Firefox Shape Path Editor, which lets floated content sculpt the flow of content, to the Variable Fonts, which enable fine-grained adjustment of font rendering, to more efficient ...

Make your web layouts bust out of the rectangle with the Firefox Shape Path Editor

CSS Shapes lets your web designs break out of the rectangular grid. Using a new CSS standard, text can flow, images can be rounded, even just a few non parallel ...

Variable Fonts Arrive in Firefox 62

Firefox 62 adds support for Variable Fonts, an exciting new technology that makes it possible to create beautiful typography with a single font file. Variable fonts are now supported in ...

Dweb: Building Cooperation and Trust into the Web with IPFS

The Interplanetary File System (IPFS) is a new protocol powered by individuals on the internet. Its goal is to “re-decentralize” the web by replacing location-oriented HTTP with a content-oriented protocol ...

Share your favorite images and videos in VR with Mozilla Hubs

Mozilla Hubs is a VR chat system that lets you walk and talk in VR with your friends, no matter where in the world they are. Now you can share ...

Dweb: Serving the Web from the Browser with Beaker

Publishing and sharing is core to the Web’s ethos, yet to publish your own website or even just share a document, you need to know how to run a server, ...

Dweb: Building a Resilient Web with WebTorrent

The web is healthy when the financial cost of self-expression isn’t a barrier. This installment of the Dweb series describes WebTorrent – an implementation of the BitTorrent protocol that runs ...

MDN Changelog for July 2018: CDN tests, Goodbye Zones, and BCD

Editor’s note: A changelog is “a log or record of all notable changes made to a project. [It] usually includes records of changes such as bug fixes, new features, etc.” ...

The Video Wars of 2027

This post imagines a dystopian future where only the rich can stream video to their homes, and the democratizing forces of the internet have crumbled under corruption and greed. The ...

DWeb: Social Feeds with Secure Scuttlebutt

Scuttlebutt is a free and open source social network with unique offline-first and peer-to-peer properties. Mainstream closed platforms have become a more popular way of creating and consuming content than ...

Things Gateway 0.5 packed full of new features, including experimental smart assistant

The Things Gateway from Mozilla lets you directly monitor and control your home over the web, without a middleman. The 0.5 release of the Things Gateway is packed full of ...

Introducing the Dweb

This is the first post in a series about the distributed/decentralized web, introducing projects that cover social communication, online identity, file sharing, new economic models, as well as high-level application ...

9 Biggest Mistakes with CSS Grid

CSS Grid is groundbreaking new technology for web design. In her newest Layout Land video, Jen Simmons explains the 9 Biggest Mistakes people are making as they adopt this new ...

360° Images on the Web, the Easy Way

One of the most popular uses for VR today is 360° images and video. These are easy to discover and share online, and you don’t need to learn any new ...

MDN Changelog for June 2018

Our monthly changelog documents what happened in June to the code, data, and tools that support MDN Web Docs site. The team shipped 100+ HTML interactive examples in June. They ...

Dark Theme Darkening: Better Theming for Firefox Quantum

A team of computer science students from Michigan State University's capstone program went to work on Firefox Quantum’s Theming API. Their goal: Expand upon the existing “lightweight” Theming API in ...

AV1: next generation video – The Constrained Directional Enhancement Filter

AV1 is a new general-purpose video codec developed by the Alliance for Open Media. The alliance began development of the new codec using Google’s VPX codecs, Cisco’s Thor codec, and ...

Firefox 61 – Quantum of Solstice

Firefox 61 is now available, bringing new performance improvements that make the fox faster than ever! We're keen on the Retained Display Lists feature to improve performance while an interactive ...

Retained Display Lists for improved page performance

Display list building is the process in which we collect the set of high-level items to display on screen (borders, backgrounds, text and much more), and then sort the list, ...

A cartoon intro to DNS over HTTPS

At Mozilla, we closely track threats to users' privacy and security. This is why we've added tracking protection to Firefox and created the Facebook container extension. In today's cartoon intro, ...

Progressive Web Games

Web game developer Andrzej Mazur explores the concept of Progressive Web Games. He describes howe to use PWA features built with Web APIs for modern game development. He introduces the ...

New in Firefox 61: Developer Edition

The latest release -- Firefox 61 Developer Edition -- comes with a darker dark theme, more powerful and customizable developer tools, the new Accessibility Inspector, and numerous performance improvements like ...

Debugging Modern Web Applications

The Firefox Dev Tools team released an upgrade to the debugger’s source map support. It lets you inspect the code that you actually wrote. Combined with the ongoing work to ...

Visualizing Your Smart Home Data with the Web of Things

Today we're mashing up two very different applications to make a cool personal dashboard for investigating all our internet-connected things, and their behavior over time. We can use one of ...

Firefox 60 – Modules and More

Firefox 60 continues the evolution of Quantum. The parallel processing of Quantum CSS comes to Firefox for Android, while WebRender work is ongoing. Potch reports on two security upgrades - ...

CDN, BCD, and SVG: MDN Changelog for April 2018

The MDN engineering team reports on work accomplished in April and what's ahead in May. Some highlights: MDN Web Docs site moved to a CDN, improving page load time by ...