Slack Alternatives

Twilio offers developers a powerful API for phone services to make and receive phone calls, and send and receive text messages. Their product allows programmers to more easily integrate various communication methods into their software and programs.

See content and chat history anytime, including team chats with Skype that are visible to the whole team. Private group chats are available for smaller group conversations.

HipChat is a hosted private chat service for your company or team. Invite colleagues to share ideas and files in persistent group chat rooms. Get your team off AIM, Google Talk, and Skype — HipChat was built for business.

Users can send messages and exchange photos, videos, stickers, audio and files of any type. It provides instant messaging, simple, fast, secure and synced across all your devices.

Mattermost is modern communication from behind your firewall.

It is a cross-platform mobile messaging app for iPhone, BlackBerry, Android, Windows Phone and Nokia. It allows users to send text messages and voice messages, make voice and video calls, and share images, documents, user locations, and other media.

Rocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework. It is a great solution for communities and companies wanting to privately host their own chat service or for developers looking forward to build and evolve their own chat platforms.

Hubot is a chat bot, modeled after GitHub's Campfire bot, hubot. He's pretty cool. He's extendable with old community scripts, or new community org and your own custom scripts, and can work on many different chat services.

Free chat rooms for your public repositories. A bit like IRC only smarter. Chats for private repositories as well as organisations.

Zulip is powerful, open source team chat that combines the immediacy of real-time chat with the productivity benefits of threaded conversations. Zulip allows busy managers and others in meetings all day to participate in their teams chats.

Nexmo connects your apps directly to carriers around the world. Integrate SMS and Voice messages using one simple API. Use Nexmo Verity to register users, verify transactions, and implement two factor authentication.

This API allows you to build your own customized Telegram clients. It is 100% open for all developers who wish to create Telegram applications on our platform.

Use the Messaging API to build bots that provide personalized experiences for your users on LINE. You associate your bot with a channel on the LINE Platform. The bot works behind the LINE Official Account that is generated when you create the channel if you operate the account in bot mode.

SendBird is a Messaging SDK, Chat API, and fully managed chat infrastructure for your mobile apps and websites. Embeddable chat for iOS, Android, JavaScript, Unity, .NET.

Postscript lets you easily create and manage SMS marketing campaigns with detailed analytics designed to increase sales and revenue, not just clicks.

Whether in a 1:1 chat or a dedicated group workspace, collaborate with your team in an organized way. Share and discuss Docs, Sheets, and Slides all in one place.

Agora.io provides building blocks for you to add real-time voice and video communications through a simple and powerful SDK. You can integrate the Agora SDK to enable real-time communications in your own application quickly.

Flowdock is a web-based team chat service that integrates with your tools to provide a window into your team's activities. With the team inbox, everyone on your team can stay up to date. Stay connected with Flowdock's iOS and Android apps.

Front allows you to collaborate with your team, stay productive, and use email and social together. Currently available on Mac, Windows, Web, and Mobile.

Since RingCentral is cloud based, you enjoy the freedom to connect and manage multiple locations, devices and workers within your cloud phone system. You can easily customize users, departments, and call handling rules. No matter where you, or the users, are. You only need a high-speed Internet connection and your phone system is ready to work lightning fast, anytime and anyplace. There’s no PBX hardware.

Plivo provides basic building block APIs in the form of Plivo XML and HTTP API, to create telephony apps, so developers can completely do away with learning the nitty-gritty of the telephony plumbing.

Aircall is an app that you can install and setup in a few minutes. It lets you buy one or several phone numbers across the world, add teammates to your dashboard, and place & receive calls on your existing devices. Everything is managed inside the Aircall app.

At MessageBird we believe that communicating with a business should feel as natural as communicating with a friend. That's why our SMS, Voice and Conversations APIs continue to revolutionize company-customer interactions.

Keybase is for anyone. Imagine a Slack for the whole world, except end-to-end encrypted across all your devices. Or a Team Dropbox where the server can't leak your files or be hacked.

The Twilio API for WhatsApp provides developers all over the world with a simple, reliable, and officially supported way to use the WhatsApp Business API. They can now easily build messaging experiences that combine the ease of use of the Programmable SMS API with the global reach of WhatsApp.

It adds the clarity and emotion of face-to-face communication to your brand whether you're developing for the web, iOS, or Android. We make the integration of high-quality live video a breeze so that you can focus on building a great product.

Communicate, collaborate and connect across desktop and mobile, using familiar features such as groups, chat and video calls. Because anything is possible when people work together.

Access WeChat’s 300 million users and make your app a global phenomenon.

It is a global leader in omnichannel engagement. We help our clients and partners overcome the complexity of consumer communications & grow their business.

Sinch makes it easy for developers to add voice, messaging and SMS to their apps with just a few lines of code. Enrich your apps with communications that your users will love.

It is an open standards IP PBX that offers complete Unified Communications, out of the box. Suitable for any business size or industry it can accommodate to your every need; from mobility and status to advanced contact center features and more, at a fraction of the cost.

It is messaging for teams that focus. Designed from the ground up to make you more productive. Everything in Quill is a thread. Focus on a topic, make decisions, and stay in flow. Choose the conversations you care about and safely filter everything else, knowing that you’re not missing out.

Translate text into any language from within Slack. You can translate messages from others, your own messages, or any text. Power features include posting translations to the channel and automatically translating all messages posted to a channel.

Flock is a communication app for teams. Packed with tons of productivity features, Flock drives efficiency and boosts speed of execution.

Add powerful communication features to your mobile app and data services for your backend<br>

Twist is a communication app for teams who believe there’s more to work than keeping up with group chat apps, created by the makers of Todoist.

Lita is a chat bot written in Ruby with persistent storage provided by Redis. It uses a plugin system to connect to different chat services and to provide new behavior. The plugin system uses the familiar tools of the Ruby ecosystem: RubyGems and Bundler.

It is a group-oriented messaging platform with an integrated suite of collaboration tools that is tailor-made for workplaces in Asia

A Communications Platform as a Service company offering a full suite of voice, messaging, and 9-1-1 APIs, all built atop the company's own all-IP voice network.

It is a business communication app that includes real-time messaging, task management and automation. You can share files and make audio or video calls, right from within your chat channels. it is loaded with features to keep teams productive and cohesive.

It supports end to end encryption, groups, channels and sharing of files between users, also registration does not require a phone number.

It is a group chat app for business. Secure messaging, video chat, task management and file sharing. Real-time communication and increase productivity for teams.

It is a free messaging application that combines chat & messaging services into one application.

The community platform for the future.

It is a cross-platform messaging app. Privacy isn’t an optional mode – it’s just the way that Signal works. Every message, every call, every time.

Campfire is like instant messaging, but designed exclusively for groups. Share text, files, and code in real time. Save transcripts so you don’t forget.

Chatkit is designed to make it as simple as possible to add chat to your app. It lets you add 1-1 and group chat to your app, along with typing indicators, file attachments and storage, user online presence and a flexible permissions system.

Chat API and SDK. With a beautiful UI Kit, easy to use React Components and powerful API. Add Chat to any application in a matter of hours. The tech uses Go, RocksDB and Raft. By the creators of Stream, the API that powers activity feeds for more than 300 million users.

Let's Chat is a persistent messaging application that runs on Node.js and MongoDB. It's designed to be easily deployable and fits well with small, intimate teams. It's free (MIT licensed) and ships with killer features such as LDAP/Kerberos authentication, a REST-like API and XMPP support.

Bring all the right people together instantly with built-in voice and video meetings. Turn conversations into action with integrated collaboration tools. Find the space to focus so you can get to done faster.