Blackfire.io vs Skylight: What are the differences?

What is Blackfire.io? Blackfire Profiler automatically instruments your code to gather data about consumed server resources like memory, CPU time, and I/O. Blackfire achieves a new level of accuracy by aggregating several profile samples and getting rid of non relevant data. Get even deeper and review the interactions with your entire stack (SQL database engines, cache servers, ...).

What is Skylight? The smart profiler for your Rails apps. Skylight is a smart profiler for your Rails apps that visualizes request performance across all of your servers.

Blackfire.io and Skylight belong to "Performance Monitoring" category of the tech stack.

Some of the features offered by Blackfire.io are:

• Profile a page at a mouse click thanks to the Blackfire web browser extension
• Browse through the function calls and identify performance bottlenecks thanks to the Blackfire intuitive UI
• Because Blackfire is only triggered when you profile a request, there is no overhead for other requests

On the other hand, Skylight provides the following key features:

• Skylight looks at how your code is behaving in production, alerting you to improvements you can make before they become showstoppers.
• Skylight tells you exactly how your app is spending its time where it matters most—in your production environment
• Pricing starts at $20 for the first million requests, with automatic discounts for high-volume customers

"Deep insights into PHP request cycle" is the top reason why over 4 developers like Blackfire.io, while over 10 developers mention "Beautiful UI" as the leading cause for choosing Skylight.

According to the StackShare community, Skylight has a broader approval, being mentioned in 39 company stacks & 5 developers stacks; compared to Blackfire.io, which is listed in 7 company stacks and 4 developer stacks.