The latest Mozilla Firefox is trickling out – and it's an Extended Support Release (ESR).

Mozilla Firefox 140 is due today, and at the time of writing you can download it from [1]Mozilla's FTP server . Right now, only the [2]beta release notes are available. The " [3]what's new for developers " page has already been updated, though.

[4]

Firefox 140, with vertical tabs but no "AI" helper, and a separate search box for LLM-free Googling – click to enlarge

There are some handy fresh features in this version. You can right-click on a tab and unload it, meaning that its contents are cleared from memory, to be reloaded the next time you switch to it. And if you use vertical tabs, you can resize the pinned-tabs area at the top of the tab bar, which could be handy. You can optionally hide the extensions button from the toolbar.

The [5]privacy-respecting local language translation feature that started rolling out in 2023 now prioritizes the area you're currently looking at, rather than always starting at the top, and follows you as you scroll. It's easier to add custom search engines – which will help usera [6]hide the AI slop from Google , for instance. Arabic speakers now get a spellchecking dictionary.

The Pocket button has gone, though. As we reported last month, Mozilla is shutting down the [7]service it acquired in 2017 .

[8]

Android users get some new shiny, too. You can select all open tabs, and private tabs can be protected against someone grabbing your device with password or fingerprint protection.

[9]

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The [11]ESR channel means this version is the next update both for users of [12]May's Firefox 139 but also for last year's ESR version, [13]July 2024's Firefox 128 .

That in turn means that the end of the line for some legacy OSes is creeping nearer. The previous ESR, [14]Firefox 115 from July 2023 , was the last version for Windows 7 and 8.x as well as macOS 10.13 "High Sierra" and 10.14 "Mojave." That old Firefox is still in maintenance. The latest point release, [15]Firefox 115.25.0 , appeared on June 23 – so those old PCs and Macs still have a reasonably safe current browser for now. As we reported when version 128 came out, the team is keeping 115 alive as long as they can. One [16]estimate says that the 2023 ESR will get updates until this coming September.

[17]Firefox is dead to me – and I'm not the only one who is fed up

[18]Thunderbird is go: 139 follows closely on Firefox's heels

[19]Firefox 139 arrives for non-Chromium browser fans

[20]Thunderbird joins Firefox on the monthly treadmill

A new ESR version means that some downstream projects will soon see new versions, or new stable releases. We expect that the [21]Waterfox browser will get updated soon, and there will be a new [22]ESR release of the [23]Thunderbird mail, news, RSS, and chat client , too.

Existing copies of the app on Windows and macOS will start to automatically update themselves in another day or so. Most Linux users should wait for their distribution to package the new version. Ubuntu users can grab the [24]candidate version from Snapcraft already, and the tarball of 140 is already available.

[25]

For The Reg FOSS desk, Firefox is still the go-to web browser – and the Waterfox fork on Linux desktops with a global menu bar, such as Unity. This vulture didn't agree with [26]SJVN's "Firefox is dead to me" column last week, and we're mulling a counterblast. The last thing the world needs is handing more control or influence to Google.

What Mozilla needs - in this author's opinion - is better, smarter leadership. ®

Get our [27]Tech Resources



[1] https://ftp.mozilla.org/pub/firefox/releases/140.0/

[2] https://www.mozilla.org/en-US/firefox/140.0beta/releasenotes/

[3] https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/140

[4] https://regmedia.co.uk/2025/06/24/firefox-140-mac.jpg

[5] https://www.theregister.com/2023/08/31/firefox_117/

[6] https://www.theregister.com/2025/05/14/openwebsearch_eu/

[7] https://www.theregister.com/2017/02/28/mozilla_makes_firstever_acquisition_webclipping_app_pocket/

[8] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aFsf6t2VQXiXubhiu0ctLQAAAkM&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0

[9] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aFsf6t2VQXiXubhiu0ctLQAAAkM&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0

[10] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aFsf6t2VQXiXubhiu0ctLQAAAkM&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0

[11] https://www.mozilla.org/en-US/firefox/enterprise/

[12] https://www.theregister.com/2025/05/28/firefox_139/

[13] https://www.theregister.com/2024/07/11/firefox_128_new_esr/

[14] https://www.mozilla.org/en-US/firefox/115.0/releasenotes/

[15] https://www.mozilla.org/en-US/firefox/115.25.0/releasenotes/

[16] https://whattrainisitnow.com/release/?version=140

[17] https://www.theregister.com/2025/06/17/opinion_column_firefox/

[18] https://www.theregister.com/2025/05/29/thunderbird_139/

[19] https://www.theregister.com/2025/05/28/firefox_139/

[20] https://www.theregister.com/2025/04/30/firefox_thunderbird_138/

[21] https://www.theregister.com/2021/11/04/waterfox_firefox_fork/

[22] https://developer.thunderbird.net/releases/channels

[23] https://www.thunderbird.net/

[24] https://snapcraft.io/firefox

[25] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aFsf6t2VQXiXubhiu0ctLQAAAkM&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0

[26] https://www.theregister.com/2025/06/17/opinion_column_firefox/

[27] https://whitepapers.theregister.com/