Firefox Profiler Deployment (June 16, 2026)

Firefox Tooling Announcements
1

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

Highlights:

  • [Nazım Can Altınova] Add source map symbolication and source view support (#6018)
    • It requires Firefox changes that will land in Firefox 154, but after these changes, you will be able to see the source mapped function names as well as the source contents!
  • [fatadel] Upgrade to React 19 (#6067)
  • [fatadel] Drive counter tooltips from a tooltipRows schema (#6023)
  • [Markus Stange] Support reading profiles from JsonSlabs files (#6037)
  • [fatadel] Replace the footer-links overlay with a settings menu (#6042)

Other Changes:

  • [Nazım Can Altınova] Fix call node context menu being hidden behind source view bottom box (#6045)
  • [Nazım Can Altınova] Pass --use-env-proxy only when the node version is >= 24 (#6064)
  • [fatadel] Upgrade @firefox-devtools/react-contextmenu to 5.2.4 (#6066)
  • [Markus Stange] Switch profiler-edit from minimist to commander (#6065)
  • [Florian Quèze] Don’t fail profile processing when a marker’s stack field is not a backtrace (#6069)
  • [fatadel] Remove unused undici-types package (#6074)
  • [cathaysia] Update isLocalURL to include LAN addresses, .local domains, and hostn… (#5973)
  • [Markus Stange] Fix from-url with binary profiles (#6072)
  • [Markus Stange] Add an insertStackLabels helper. (#6076)
  • [fatadel] Add TrackPower–tooltip-average-power-microwatt (#6080)
  • [Markus Stange] Downgrade to React 19.1 to fix unusable dev build performance. (#6082)
  • [spokodev] fix(FilterNavigatorBar): clip overflow so many breadcrumbs do not expand the parent (#6085)
  • [Markus Stange] Move paddings inside the tree header cells. (#6002)
  • [Markus Stange] Add an --insert-label-frames argument to the profiler-edit tool (#5966)
  • [Markus Stange] Stop printing “error: too many arguments” during tests. (#6088)
  • [Markus Stange] More additions to profiler-edit, for sp3 profiles (#6009)
  • [Nazım Can Altınova] Do not rely on localized texts in the settings menu tests (#6101)

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

  • be: Andrei Mukamolau
  • de: Ger
  • de: Michael Köhler
  • de: Ralf Duehnfahr
  • el: Jim Spentzos
  • en-CA: chutten
  • en-GB: Ian Neal
  • es-CL: ravmn
  • fr: Théo Chevalier
  • fr: wy
  • fur: Fabio Tomat
  • fy-NL: Fjoerfoks
  • ia: Melo46
  • it: Francesco Lodolo [:flod]
  • nl: Mark Heijl
  • ru: Valery Ledovskoy
  • sr: Марко Костић (Marko Kostić)
  • sv-SE: Andreas Pettersson
  • tr: Grk
  • tr: Selim Şumlu
  • zh-CN: Olvcpr423
  • 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!