Phasing Out the Older Version of Firefox Sidebar in 2026
Over a year ago, we introduced an updated version of the sidebar that offers easy access to multiple tools – bookmarks, history, tabs from other devices, and a selection of … Read more
Articles in “Uncategorized”
Firefox Sidebar and Vertical tabs: try them out in Nightly Firefox Labs 131
We are excited to share that vertical tabs and a new sidebar experience are now available in Nightly 131. This update has been highly anticipated and requested by the community, … Read more
These Weeks in Firefox: Issue 102
Highlights As part of Fission-related changes, browser.tabs.delectLanguage has been migrated away from MessageChannel.jsm and to use the JSWindowActor messaging instead, which has also nicely reduced AWSY’s Base Content JS memory … Read more
These Weeks in Firefox: Issue 101
Highlights We have begun to roll out fission to a fraction of users on the release channel! Here’s a reminder of what Fission is, and why it matters Telemetry so … Read more
These Weeks in Firefox: Issue 95
Headlines Firefox 89 released this week! This version includes a major UI redesign and thoughtful touches throughout. See the release notes here. We launched ideas.mozilla.org, a new platform for the … Read more
These Weeks in Firefox: Issue 94
Highlights On macOS, scrollbars now squish during rubber-banding. We’re working on supporting native fullscreen on macOS. Turn it on by enabling the pref full-screen-api.macos-native-full-screen. This will (among other things) create … Read more
These Weeks in Firefox: Issue 89
Highlights Visualization of the CPU utilization is landing soon! Example profile (currently deploy preview) You can toggle the new/old visualization from the “graph type” radio button on the top left … Read more
These Weeks in Firefox: Issue 88
Highlights Firefox 86 went out on February 23rd! Here are the release notes. The new, modern printing UI is rolling out to 100% of our release users in Firefox 86! … Read more
These Weeks in Firefox: Issue 82
Highlights Urlbar Update 2 enabled on Firefox Beta. This work includes Search Mode, refreshed one-offs, and tab-to-search results. We recently introduced tab-to-search results that are shown when a search engine’s … Read more
These Weeks in Firefox: Issue 80
Highlights We now show three recommended articles when saving a webpage to Pocket. To enable this, set extensions.pocket.onSaveRecs to true, and restart. This is an enhancement and thus will be … Read more
These Weeks in Firefox: Issue 76
Highlights Call for testing: turn on the devtools.netmonitor.features.sse pref, which provides support for Server Side Events (SSE) ready in 80 and a visualization for text/event-stream content types (bug). Use this … Read more
Reducing Notification Permission Prompt Spam in Firefox
Permission prompts are a common sight on the web today. They allow websites to prompt for access to powerful features when needed, giving users granular and contextual choice about what … Read more