Support/Firefox151

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Firefox 151 release information

Disclaimer

The following information is intended for members of the Mozilla Support community for the purpose of supporting users in the Mozilla Support platform. Mozilla Support is a community of enthusiastic volunteers and employees trying to support Mozilla's users around the globe. You can join us by contributing through the following ways:

• Answer questions in the support forum
• Write help articles
• Localize support content

To learn more about how to stay updated with Firefox release information, trending, and known issues, please also check out How to stay updated with Firefox release

Release notes

• Desktop 151.0 Release Notes
• ESR 140.11.0 Release Notes
• ESR 115.36.0 Release Notes
• Firefox for Enterprise 151 Release Notes
• Firefox for developers 151 Release Notes
• Firefox for Android 151.0 Release Notes
• Firefox for iOS 151.0 Release Notes

Dot releases

Platform	Version	Release date	Notable fixes	Unresolved
Firefox Desktop	151.0.1	May 21, 2026	bug1950764, bug2040754	-
Firefox Desktop	151.0.2	May 26, 2026	Various bug fixes	-
Firefox for Android	151.0.1	May 26, 2026	bug 2041355	-

Contributor discussions

Please refer to the following contributor forum threads to learn more about known issues and discuss with other contributors:

• Desktop release discussion
• Mobile release discussion
• Localization discussion

You can also join our Matrix channel to ask questions/join community discussion.

Stay updated

Apart from sharing release information, there are other ways to stay updated with product release and community updates:

• Community call: We run a monthly community call (usually on the same week we release a new Firefox version). Check our schedule here and don't hesitate to join the call in person if you can!
• Newsletter: Consider subscribing to Firefox Daily Digest to get daily updates (Mon-Fri) about Firefox from across the internet.

What's new in Firefox 151

Content in this page is being updated periodically as we're rolling out the release.

Firefox Desktop content update

Merge PDF section
Description:	Add new PDF editing features to "view/edit" article: Merge (Firefox desktop 151) to SUMO article
Content request:	bug 2038255
KB article:	view-pdf-files-firefox-or-choose-another-viewer	Article update

New tab update [Nova]
Description:	Updates to New Tab SUMO pages for Nova
Content request:	bug 2030282
KB articles:	about-new-tab-page	Article update
	customize-items-on-firefox-new-tab-page
	firefox-new-tab-widgets

Built-in VPN: Choose location
Description:	Update the existing built-in VPN KB article to add locations
Content request:	bug 2031491
KB article:	built-in-vpn	Article update

Model choices in Smart Window
Description:	Update "Model choices in Smart Window" sumo article
Content request:	bug 2038341
KB article:	smart-window-models	Article update

GCI statement
Description:	-
Content request:	bug 2039950
KB article:	accessing-cloud-supported-features-firefox	New article

Clear Private Browsing session (fire button)
Description:	Add a section to the Private Browsing page about the "Clear Private Browsing"/fire button
Content request:	bug 2039917
KB article:	TBD	Article update

Built in VPN Territory expansion (June 2nd-June 3rd)
Description:	Firefox for Desktop is expanding VPN availability to more countries.
Content request:	bug 2041510
KB article:	https://support.mozilla.org/en-US/kb/built-in-vpn	Article update

Firefox for Android content update

Shake to summarize on Android
Description:	New SUMO article about Shake to Summarize feature on Android
Content request:	bug 2022694
KB article:	summarize-pages-android	New article

AI controls on Android
Description:	-
Content request:	bug 2030406
KB article:	android-ai-controls	New article

Built-in VPN on Android (moved to future version)
Description:	VPN android early access
Content request:	bug 2030084
KB article:	placeholder-android-vpn	New article

Firefox for iOS content update

AI Controls on iOS
Description:	New KB article for AI Controls on iOS
Content request:	bug 2030407
KB article:	ios-ai-controls	New article

Product discussions on Mozilla Connect

Check out top voted requests on Mozilla Connect.

• A Fresh New Look for Home & New Tab (Desktop)
• Help shape Tab Groups on Firefox Mobile for Android!
• Share Your Feedback on the New Firefox Redesign

Known issues

Platform	Issue	Known bug/Related discussions	Fix/workaround
Desktop	VPN button becomes huge	bug2042454	Fixed in 151.0.3
Android	Open tabs are also gone when browsing history is selected in Delete browsing data on quit	bug2033285	Fixed in 152

Known incidents

"Clear cache" prompt on Firefox Android Nightly
Description:	Users are getting a system notification recommending they clear cache.
Status:	Ongoing
Product(s) impacted:	Firefox for Android (Nighlty version)
Associated bug:	bug2040753
Resolution/workaround:	TBD

webserial failure to open port
Description:	WebSerial can fail to open a port that was just closed
Status:	Ongoing
Product(s) impacted:	Firefox Desktop
Associated bug:	bug2040754
Resolution/workaround:	Will be fixed in the upcoming dot release

Fire button doesn't appear
Description:	The fire button to clear PBM session doesn't appear for the subset of users
Status:	Fixed
Product(s) impacted:	Firefox Desktop
Associated bug:	bug2040918
Resolution/workaround:	The Nimbus experiment has been fixed