Download Firefox Developer Edition (eo) 140.0

New
- You can now unload tabs by right-clicking on a tab (or multiple selected tabs) and selecting "Unload Tab". This can be helpful in reducing Firefox's memory and CPU usage.
- Firefox for Android now allows includes a "Select All" in Bookmarks.
- Vertical Tabs: You can now keep more — or fewer — pinned tabs in view. Just drag the divider to resize your pinned tabs section.
- Firefox now supports adding custom search engines. To do so, right-click a search field of a supported website and select Add Search Engine, or go to Settings > Search > Add (below the search shortcuts table) to manually enter a search URL.
- The Firefox Extensions button can now be removed from the toolbar, giving you more control over how you customize your browser. When the button is hidden, you can access the extensions panel again at any time from the Firefox menu by clicking the Extensions menu item.
- Firefox builds in Arabic now come with a built-in Arabic dictionary for the Firefox spellchecker.
- You can now lock your private browsing tabs behind your fingerprint or device credentials for added privacy. Enable the setting in Firefox for Android to keep your private tabs secure even when you leave the app.
- Full-Page Translations now prioritize translating only the content near your current view, improving speed and responsiveness. Content outside your view is skipped unless you scroll to it, reducing unnecessary resource usage.
Changed
- The Pocket toolbar icon, as well as the Pocket integrations on New Tab, have been removed per the service shutdown announcement.
Developer

Web Platform
- Service Workers are now available in 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.
- Added Platform support for aria-keyshortcuts in Linux, MacOS, and Windows.
- Added support for the CookieStore API, an asynchronous cookie API for scripts running in HTML documents and service workers.
- Added support for the Custom Highlight API, which allows to style text ranges.
- On all platforms, Firefox now applies a uniform user agent (UA) style to <h1> elements, regardless of whether they are used inside <article>, <aside>, <nav>, or <section>.
- Firefox now supports the pointerrawupdate event. This event provides lower-latency access to pointer movements by firing as soon as the pointer data is available, typically before the main pointermove event. Unlike pointermove, it performs an additional hit test to determine the target, and fires more frequently, which may impact performance even if only a listener is added. This event is intended for applications that require high-precision input handling and cannot achieve smooth interaction using coalesced pointermove events alone.
- Firefox will now escape less-than (<) and greater-than (>) symbols when serializing HTML attributes, making certain mXSS attacks on websites more difficult.