#Firefox 139 Open-Source Web Browser Is Now Available for Download, Here’s What’s New https://9to5linux.com/firefox-139-web-browser-is-now-available-for-download-heres-whats-new
-
#Firefox 139 Open-Source Web Browser Is Now Available for Download, Here’s What’s New https://9to5linux.com/firefox-139-web-browser-is-now-available-for-download-heres-whats-new
-
#Firefox 139 Open-Source Web Browser Is Now Available for Download, Here’s What’s New https://9to5linux.com/firefox-139-web-browser-is-now-available-for-download-heres-whats-new
Mozilla published today the final build of the Firefox 139 open-source web browser ahead of the official announcement on May 27th, 2025.
Mozilla Firefox 139 looks like a small update that only introduces support for full-page translations within Firefox extension pages, support for transparent PNG images when they’re pasted into Firefox, and improved upload performance of HTTP/3.
For web developers, Firefox 139 promises timer throttling support for Workers, support for the WebAuthn largeBlob extension, support for requestClose() to HTMLDialogElement, and support for the hidden=until-found attribute, which allows content to be found via find-in-page when it’s otherwise hidden by default.
In addition, Firefox 139 looks to enable the Temporal proposal by default as a better replacement for Date, make closed <details> elements searchable and automatically expand them if found via find-in-page, improve cross-browser interoperability on some sites, and bring Service Workers to the Private Browsing Mode.
“This enhancement builds on our efforts to support IndexedDB and the DOM Cache API in Private Browsing through encrypted storage. With this change, more websites, especially those that rely on background tasks, will be able to benefit from Service workers,” said Mozilla.Last but not least, this release updates the built-in editor for contenteditable and designMode to handle collapsible white-space(s) before block boundaries and white-space sequences between visible content more consistently with Chrome, aligning Firefox’s behavior with other web browsers.
As mentioned before, Mozilla plans to officially announce Firefox 139 on May 27th, 2025, along with the Firefox 115.24 and Firefox 128.11 ESR releases. Until then, you can download the binaries from Mozilla’s FTP server.
-
#Firefox 139 Open-Source Web Browser Is Now Available for Download, Here’s What’s New https://9to5linux.com/firefox-139-web-browser-is-now-available-for-download-heres-whats-new
