Firefox Profiler Deployment (March 3, 2026)

The latest version of the Firefox Profiler is now live! Check out the full changelog below to see what’s changed.

Highlights:

  • [fatadel] Persist selected marker in URL and show sticky tooltip on load (#5847)
  • [Markus Stange] Implement the “collapse resource” transform with the help of the “collapse direct recursion” transform. (#5824)
  • [Markus Stange] Share stackTable, frameTable, funcTable, resourceTable and nativeSymbols between threads (#5482)
  • [fatadel] Add support for ternaries in marker labels (#5857)

Other Changes:

  • [fatadel] Fix crash when nativeSymbol index is out of bounds in assembly view (#5850)
  • [Nazım Can Altınova] Fix the color of dark mode back arrow svg (#5863)
  • [fatadel] Force canvas redraw when system theme changes (#5861)
  • [Nazım Can Altınova] Fix unhandled promise rejection in setupInitialUrlState (#5864)
  • [Markus Stange] Remove async attribute from module script tag. (#5870)
  • [Nazım Can Altınova] Update the docsify package that’s used in the user documentation (#5872)
  • [Nazım Can Altınova] Escape CSS URLs that are coming from profiles (#5874)
  • [fatadel] Update home page message for the other browser case (#5866)
  • [Markus Stange] Reduce allocations for getStackLineInfo + getStackAddressInfo (#5761)

Big thanks to our amazing localizers for making this release possible:

  • de: Ger
  • fy-NL: Fjoerfoks
  • it: Francesco Lodolo [:flod]
  • nl: Fjoerfoks
  • ru: berry
  • ru: Valery Ledovskoy
  • zh-TW: Pin-guang Chen

Find out more about the Firefox Profiler on profiler.firefox.com! If you have any questions, join the discussion on our Matrix channel!