Recordings launch profiler.firefox.com in a new tab. All data is stored locally, but you can choose to upload it for sharing.
Recommended preset for most web app debugging, with low overhead.
Recommended preset for internal Firefox platform debugging.
Recommended preset for internal Firefox front-end debugging.
Recommended preset for Firefox graphics performance investigation.
Recommended preset for diagnosing audio and video problems.
Bypass selections above and record all registered threads
Add custom threads by name:
Features (Recommended on by default)
Record native stacks (C++ and Rust). This is not available on all platforms.
Record how much CPU has been used between samples by each profiled thread.
Native Leaf Stack
Record the native memory address of the leaf-most stack. This could be useful on platforms that do not support stack walking.
No Periodic Sampling
Disable interval-based stack sampling
Main Thread File IO
Record main thread File I/O markers.
Profiled Threads File IO
Record File I/O markers from only profiled threads.
All File IO
Record File I/O markers from all threads, even unregistered threads.
No File IO Stack Sampling
Do not sample stacks when recording File I/O markers.
Disable parallel traversal in styling.
Record screenshots of all browser windows.
Track Preference Reads
Track IPC messages.
Audio Callback Tracing
Trace real-time audio callbacks.
Profile Java code
This feature is only available on Android.
TaskTracer requires a custom build with the environment variable MOZ_TASK_TRACER set.
Trace JS engine
JS Tracer is currently disabled due to crashes. See Bug 1565788.
Track native allocations
If you’re profiling a build that you have compiled yourself, on this machine, please add your build’s objdir to the list below so that it can be used to look up symbol information.