Firefox 139 arrives for non-Chromium browser fans
(2025/05/28)
- Reference: 1748446326
- News link: https://www.theregister.co.uk/2025/05/28/firefox_139/
- Source link:
Another month, another new version of Firefox, with several handy changes. The future is less certain, though.
Mozilla has released Firefox 139, but the new version is overshadowed by the company's other recent changes. The [1]announcement page for the new release really is startlingly bare: there are no new features listed at all. There's just a link to Mozilla's blog post from last week about [2]a smarter, simpler Firefox address bar .
That's a little unjust. There are some new features in this version, as the [3]release notes explain. Mozilla's privacy-first, local-to-your-computer translation feature, which we [4]described in summer 2023 , is now even more capable, and it can translate foreign-language content that's come from Firefox extensions. You can now also customize the new tab page, and you can optionally enable a feature to display previews of links. If you copy a PNG image then paste it into Firefox, it will now keep any transparency. Uploads of large files should be faster over HTTP3, too. There are also some beneath-the-hood [5]changes for developers but they aren't too dramatic.
[6]
The changes to the address bar bring across some functions from the long-deprecated Firefox search box. You can use keywords to change search engine – such as to use a [7]custom Google query which strips AI slop , for instance. There are commands to control app functionality, like clear history and open downloads , which sound handy. Some of these features were already available in the previous release, though.
[8]
[9]
Features like this are very welcome. We said [10]Firefox was the power users' browser back in 2022, and [11]implored Mozilla to lean into this the following year.
Unfortunately, though, some of the other news coming out of Mozilla – as we mentioned [12]last week – is less reassuring. [13]Eight years ago , Mozilla made its first-ever acquisition, a tool called Pocket for saving pages to read later. In 2023, it [14]bought Fakespot , and we reported on the service's planned integration [15]later that year . Well, both face the chop in July: the day before it blogged about its improved address bar, Mozilla [16]announced both will go offline .
[17]
The most noticeable other change from Mozilla this month is that the primary repository for Firefox's source code is now [18]Mozilla's Github repo . Mozilla previously used Mercurial, and for now [19]those repositories are still running. Mozilla is following an industry trend here, as others organizations from [20]the SDL project to Jira perpetrators [21]Atlassian's Bitbucket have done in recent years.
Arc is sinking, too
Things are no easier over the fence in the land of Chromium-based browsers, as The Register noted [22]last night . A couple of years ago, we looked at the [23]experimental new Arc web browser , which attempted to revamp the established browser UI. Arc is able to tile web pages within a single browser window, which could be very useful for the many people who haven't mastered the tiling features built into many OSes and desktops these days.
It also had a vertical tab bar, which regular readers will have worked out is a Reg FOSS desk essential feature, but also cleverly merged a vertical bookmark bar into the tab bar, which was very nifty.
Well, not any more. This arc has an endpoint, as the Browser Company said yesterday it was [24]ending development of Arc . Instead, it is — hypothetical deities help us — pivoting to AI, and is now working on a new AI-powered browser, [25]to be called Dia .
[26]Arc put on ice as The Browser Company bets big on AI-powered Dia
[27]Glitch hits kill switch on app web hosting, citing 'bad actors' and worse architecture
[28]Trump's 'Big Beautiful Bill' would create a regulation-free AI hellscape, AGs warn
[29]If Google is forced to give up Chrome, what happens next?
That looks like it leaves the Firefox-based [30]Zen browser as the main project experimenting with tiling browsers. We [31]took a look at Zen last year, and rather liked it. There have been about 12 point releases since then.
We'd almost suggest that Mozilla bought Zen and placed its designers in charge of Firefox ... but judging by recent trends, the organization would probably only end up shutting the project down after a few years. ®
Bootnote
The phrase "Pivot to AI" is a reference to AI and blockchain industry commentator David Gerard's [32]intensely skeptical news blog . Although The Register and Gerard have occasionally [33]had differences in the [34]distant past , that was a long time ago, and The Reg has subsequently [35]quoted him on Bitcoin matters as well as the [36]nebulous "Web 3" . This vulture heartily recommends perusal of Pivot to AI.
Get our [37]Tech Resources
[1] https://www.mozilla.org/en-GB/firefox/139.0/whatsnew/
[2] https://blog.mozilla.org/en/firefox/address-bar/
[3] https://www.mozilla.org/en-US/firefox/139.0/releasenotes/
[4] https://www.theregister.com/2023/08/31/firefox_117/
[5] https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/139
[6] 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=2aDczFDzVZggAx8dtVS6x4QAAANQ&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[7] https://www.theregister.com/2025/05/14/openwebsearch_eu/
[8] 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=44aDczFDzVZggAx8dtVS6x4QAAANQ&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%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=3&c=33aDczFDzVZggAx8dtVS6x4QAAANQ&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[10] https://www.theregister.com/2022/09/26/firefox_power_user_guide/
[11] https://www.theregister.com/2023/09/29/mozilla_asleep_at_wheel/
[12] https://www.theregister.com/2025/05/23/glitch_app_hosting_gone/
[13] https://www.theregister.com/2017/02/28/mozilla_makes_firstever_acquisition_webclipping_app_pocket/
[14] https://blog.mozilla.org/en/mozilla/fakespot-joins-mozilla-firefox-shopping-announcement/
[15] https://www.theregister.com/2023/10/26/firefox_119_and_120/
[16] https://blog.mozilla.org/en/mozilla/building-whats-next/
[17] 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=44aDczFDzVZggAx8dtVS6x4QAAANQ&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[18] https://github.com/mozilla-firefox/firefox
[19] https://hg-edge.mozilla.org/
[20] https://www.theregister.com/2021/02/10/sdl_moves_to_github/
[21] https://www.theregister.com/2019/08/21/bitbucket_mercurial_repositories/
[22] https://www.theregister.com/2025/05/27/arc_browser_development_ends/
[23] https://www.theregister.com/2023/07/31/arc_a_radical_new_browser/
[24] https://browsercompany.substack.com/p/letter-to-arc-members-2025
[25] https://www.diabrowser.com/
[26] https://www.theregister.com/2025/05/27/arc_browser_development_ends/
[27] https://www.theregister.com/2025/05/23/glitch_app_hosting_gone/
[28] https://www.theregister.com/2025/05/20/trump_bill_regulation_free_ai/
[29] https://www.theregister.com/2025/05/09/opinion_column_google_chrome_potential_divestiture/
[30] https://zen-browser.app/
[31] https://www.theregister.com/2024/09/02/zen_firefox_fork_alpha/
[32] https://pivot-to-ai.com/
[33] https://www.theregister.com/2009/12/02/the_end_of_the_wikipedia_good_old_boys_club/
[34] https://www.theregister.com/2009/02/27/what_is_the_reg/
[35] https://www.theregister.com/2018/04/12/javascript_crypto_library_fingered_for_weak_wallets/
[36] https://www.theregister.com/2021/12/15/web3_apparently_the_next_generation/
[37] https://whitepapers.theregister.com/
Mozilla has released Firefox 139, but the new version is overshadowed by the company's other recent changes. The [1]announcement page for the new release really is startlingly bare: there are no new features listed at all. There's just a link to Mozilla's blog post from last week about [2]a smarter, simpler Firefox address bar .
That's a little unjust. There are some new features in this version, as the [3]release notes explain. Mozilla's privacy-first, local-to-your-computer translation feature, which we [4]described in summer 2023 , is now even more capable, and it can translate foreign-language content that's come from Firefox extensions. You can now also customize the new tab page, and you can optionally enable a feature to display previews of links. If you copy a PNG image then paste it into Firefox, it will now keep any transparency. Uploads of large files should be faster over HTTP3, too. There are also some beneath-the-hood [5]changes for developers but they aren't too dramatic.
[6]
The changes to the address bar bring across some functions from the long-deprecated Firefox search box. You can use keywords to change search engine – such as to use a [7]custom Google query which strips AI slop , for instance. There are commands to control app functionality, like clear history and open downloads , which sound handy. Some of these features were already available in the previous release, though.
[8]
[9]
Features like this are very welcome. We said [10]Firefox was the power users' browser back in 2022, and [11]implored Mozilla to lean into this the following year.
Unfortunately, though, some of the other news coming out of Mozilla – as we mentioned [12]last week – is less reassuring. [13]Eight years ago , Mozilla made its first-ever acquisition, a tool called Pocket for saving pages to read later. In 2023, it [14]bought Fakespot , and we reported on the service's planned integration [15]later that year . Well, both face the chop in July: the day before it blogged about its improved address bar, Mozilla [16]announced both will go offline .
[17]
The most noticeable other change from Mozilla this month is that the primary repository for Firefox's source code is now [18]Mozilla's Github repo . Mozilla previously used Mercurial, and for now [19]those repositories are still running. Mozilla is following an industry trend here, as others organizations from [20]the SDL project to Jira perpetrators [21]Atlassian's Bitbucket have done in recent years.
Arc is sinking, too
Things are no easier over the fence in the land of Chromium-based browsers, as The Register noted [22]last night . A couple of years ago, we looked at the [23]experimental new Arc web browser , which attempted to revamp the established browser UI. Arc is able to tile web pages within a single browser window, which could be very useful for the many people who haven't mastered the tiling features built into many OSes and desktops these days.
It also had a vertical tab bar, which regular readers will have worked out is a Reg FOSS desk essential feature, but also cleverly merged a vertical bookmark bar into the tab bar, which was very nifty.
Well, not any more. This arc has an endpoint, as the Browser Company said yesterday it was [24]ending development of Arc . Instead, it is — hypothetical deities help us — pivoting to AI, and is now working on a new AI-powered browser, [25]to be called Dia .
[26]Arc put on ice as The Browser Company bets big on AI-powered Dia
[27]Glitch hits kill switch on app web hosting, citing 'bad actors' and worse architecture
[28]Trump's 'Big Beautiful Bill' would create a regulation-free AI hellscape, AGs warn
[29]If Google is forced to give up Chrome, what happens next?
That looks like it leaves the Firefox-based [30]Zen browser as the main project experimenting with tiling browsers. We [31]took a look at Zen last year, and rather liked it. There have been about 12 point releases since then.
We'd almost suggest that Mozilla bought Zen and placed its designers in charge of Firefox ... but judging by recent trends, the organization would probably only end up shutting the project down after a few years. ®
Bootnote
The phrase "Pivot to AI" is a reference to AI and blockchain industry commentator David Gerard's [32]intensely skeptical news blog . Although The Register and Gerard have occasionally [33]had differences in the [34]distant past , that was a long time ago, and The Reg has subsequently [35]quoted him on Bitcoin matters as well as the [36]nebulous "Web 3" . This vulture heartily recommends perusal of Pivot to AI.
Get our [37]Tech Resources
[1] https://www.mozilla.org/en-GB/firefox/139.0/whatsnew/
[2] https://blog.mozilla.org/en/firefox/address-bar/
[3] https://www.mozilla.org/en-US/firefox/139.0/releasenotes/
[4] https://www.theregister.com/2023/08/31/firefox_117/
[5] https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/139
[6] 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=2aDczFDzVZggAx8dtVS6x4QAAANQ&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[7] https://www.theregister.com/2025/05/14/openwebsearch_eu/
[8] 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=44aDczFDzVZggAx8dtVS6x4QAAANQ&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%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=3&c=33aDczFDzVZggAx8dtVS6x4QAAANQ&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[10] https://www.theregister.com/2022/09/26/firefox_power_user_guide/
[11] https://www.theregister.com/2023/09/29/mozilla_asleep_at_wheel/
[12] https://www.theregister.com/2025/05/23/glitch_app_hosting_gone/
[13] https://www.theregister.com/2017/02/28/mozilla_makes_firstever_acquisition_webclipping_app_pocket/
[14] https://blog.mozilla.org/en/mozilla/fakespot-joins-mozilla-firefox-shopping-announcement/
[15] https://www.theregister.com/2023/10/26/firefox_119_and_120/
[16] https://blog.mozilla.org/en/mozilla/building-whats-next/
[17] 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=44aDczFDzVZggAx8dtVS6x4QAAANQ&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[18] https://github.com/mozilla-firefox/firefox
[19] https://hg-edge.mozilla.org/
[20] https://www.theregister.com/2021/02/10/sdl_moves_to_github/
[21] https://www.theregister.com/2019/08/21/bitbucket_mercurial_repositories/
[22] https://www.theregister.com/2025/05/27/arc_browser_development_ends/
[23] https://www.theregister.com/2023/07/31/arc_a_radical_new_browser/
[24] https://browsercompany.substack.com/p/letter-to-arc-members-2025
[25] https://www.diabrowser.com/
[26] https://www.theregister.com/2025/05/27/arc_browser_development_ends/
[27] https://www.theregister.com/2025/05/23/glitch_app_hosting_gone/
[28] https://www.theregister.com/2025/05/20/trump_bill_regulation_free_ai/
[29] https://www.theregister.com/2025/05/09/opinion_column_google_chrome_potential_divestiture/
[30] https://zen-browser.app/
[31] https://www.theregister.com/2024/09/02/zen_firefox_fork_alpha/
[32] https://pivot-to-ai.com/
[33] https://www.theregister.com/2009/12/02/the_end_of_the_wikipedia_good_old_boys_club/
[34] https://www.theregister.com/2009/02/27/what_is_the_reg/
[35] https://www.theregister.com/2018/04/12/javascript_crypto_library_fingered_for_weak_wallets/
[36] https://www.theregister.com/2021/12/15/web3_apparently_the_next_generation/
[37] https://whitepapers.theregister.com/
Vivaldi has tiling
Psy-Q
Vivaldi has had tab tiling for years. Like it already has most features that other browsers will market as "new" one day.
@Liam:
"We'd almost suggest that Mozilla bought Zen and placed its designers in charge of Firefox ... but judging by recent trends, the organization would probably only end up shutting the project down after a few years. ®"
Ooooooh..............I can feel The Burn all the way here in Toronto, Canada.