Firefox Extended Support Release (ESR) is an official version of Firefox developed for large organizations like universities and businesses that need to set up and maintain Firefox on a large scale. Firefox ESR does not come with the latest features but it has the latest security and stability fixes.

Get the Firefox Extended Support Release or Rapid Release browser for comprehensive data security and data protection.

Your data stays your business

The Firefox browser is open source, provides Enhanced Tracking Protection and soon will support DNS over HTTPS --- all part of our longstanding commitment to data protection.

Deploy when and how you want

With install packages and a wide expansion of group policies and features, deployment is faster and more flexible than ever --- and a breeze in Windows and macOS environments.

Choose your release cadence

Get rapid releases to make sure you get the latest features faster, or go extended to ensure a super stable experience.

What's New

Firefox version 115 will be the last supported Firefox version for users of Windows 7, Windows 8, Windows 8.1, macOS 10.12 (Sierra), macOS 10.13 (High Sierra) and macOS 10.14 (Mojave). If you are using these versions of Windows or macOS you will be moved to the Firefox Extended Support Release (ESR) channel by an application update. Mozilla will provide security updates for Firefox 115 ESR until March 2027, when the position will be re-evaluated.

Firefox 153 is the next ESR. Firefox 140 ESR will continue to receive security updates during the ESR transition period.

If you use the ESR, we strongly recommend testing Firefox 153 with your enterprise configuration, extensions, authentication systems, and deployment tooling. Testing during the transition period gives you time to identify and report issues before Firefox 140 ESR users are automatically upgraded to Firefox 153 ESR.

If you need to prevent upgrades for any reason, you can use the AppUpdatePin policy.

Why has Firefox ended support for Windows 7, 8 and 8.1 users?

Microsoft ended official support for Windows 7, 8 and 8.1 in January of 2023. Unsupported operating systems receive no security updates and have known exploits. With no official support from Microsoft, maintaining Firefox for obsolete operating systems becomes costly for Mozilla and dangerous for users.

Will switching to a different browser keep me protected?

No. Most browsers, including Google Chrome and Microsoft Edge, have already ended support for Windows 7, 8 and 8.1.

Can I still browse safely with Firefox Windows 7, 8 and 8.1?

Mozilla is providing critical security updates through the Firefox ESR channel up until the end of ESR version 115, August 2025. After this, no security updates are provided and you are strongly encouraged to move to a supported version of Microsoft Windows.

How can I get the newest features of Firefox?

If you want to keep your Firefox up to date, with all the latest features and updates, you need to upgrade your operating system to Windows 10 or higher. In some cases, Microsoft may require newer hardware in order to support the newer operating system. After upgrading, users can easily reinstall Firefox and keep all of their settings.

Firefox ESR 153.0 Release Notes:

Version 153.0esr, first offered to ESR channel users on July 21, 2026

Firefox 153 Extended Support Release (ESR) includes all of the enhancements since Firefox 140, along with many new features to make your enterprise deployments easier and even more flexible.

New

General

  • Firefox now includes a new profile management system that helps you separate your online life into distinct profiles for work, school, vacation planning, or whatever you choose. Profiles can be customized with names, avatars, and color themes while keeping tabs, bookmarks, passwords, and browsing history separate. Built-in profile backup and restore also makes it easier to migrate to a new device or recover your browsing data.
  • Split View lets you view two webpages side-by-side in a single browser window, with additional options to quickly open links in Split View, rearrange pages, and search open tabs.
  • The Firefox address bar has gained several new capabilities, including built-in unit and time zone conversion, quick actions such as muting all browser audio, and direct search results as you type.
  • Firefox now supports copying links directly to highlighted text on a webpage for easier sharing.
  • Firefox Settings has been redesigned with improved organization and navigation, making it easier to find and customize browser preferences.

AI

  • Firefox introduced several new AI-powered features, including on-device tab organization, AI-assisted link previews, integrated AI search, and centralized controls for managing AI features. Whenever possible, these features perform processing locally to help protect user privacy.

Sidebar and Tabs

  • Firefox continues to improve tab management with enhancements to vertical tabs, tab groups, and the sidebar.
  • Tab groups have gained numerous usability improvements, including better support for collapsed groups, previews of grouped tabs, and additional organization options.
  • Passwords can now be accessed directly from the Firefox sidebar without opening a separate tab.
  • Firefox now supports copying links from one or multiple background tabs directly from the tab context menu, and multiple tabs can be copied or shared in a single action.
  • A Send Tab toolbar button is now available through Customize Toolbar.

Security & Privacy

  • Firefox has significantly expanded Fingerprinting Protection, making it harder for websites to uniquely identify users in both Standard and Strict Enhanced Tracking Protection modes.
  • Enhanced Tracking Protection includes stronger protections against bounce tracking and additional safeguards that restrict websites from accessing local network resources without user permission.
  • Firefox now uses Safe Browsing V5 for phishing and malware protection.
  • Firefox Password Manager now uses stronger AES-256 encryption to protect stored logins on disk.
  • Private Browsing has been enhanced with new controls, including the ability to instantly end a private browsing session and temporarily relax tracker blocking for individual sites when needed for compatibility.

Translations

  • Firefox has expanded on-device translation support with many additional languages and continued improvements to translation quality.
  • A dedicated translations page now provides an easy way to perform real-time translations directly within Firefox.

Accessibility

  • Firefox continues to improve accessibility with enhanced support for assistive technologies, including Windows UI Automation, improved keyboard navigation, more accessible date and time controls, and better support for mathematical content in PDFs.

Windows

  • Firefox now supports installing websites as standalone web apps pinned to the Windows taskbar.
  • Firefox web apps are also available for Microsoft Store installations.
  • Firefox now better integrates with Windows location permissions when websites request geolocation access.

macOS

  • Firefox now uses a dedicated GPU process by default, improving stability by allowing graphics failures to recover without restarting the browser.
  • WebGPU is now enabled by default on Apple Silicon Macs.

Linux

  • Firefox now supports native fractional scaling on Wayland, improving rendering on high-DPI displays.
  • Firefox no longer requires a restart after package manager updates and uses less memory on Linux.
  • Firefox now supports the XDG Base Directory Specification and ships with RPM packages for Red Hat, Fedora, openSUSE, and other RPM-based distributions.

Fixed

  • Various security fixes.

Enterprise

  • Enterprise administrators can now centrally manage Firefox's Generative AI features through enterprise policy.
  • Fixed a performance regression affecting native messaging, improving responsiveness for enterprise extensions that communicate with external applications.
  • Enterprise policy documentation has moved to https://firefox-admin-docs.mozilla.org/.

Web Platform

  • Firefox now supports the View Transitions API for creating smooth animated transitions between application views.
  • WebGPU support has expanded across supported platforms, including Windows and Apple Silicon Macs.
  • Added support for several modern web platform APIs, improving compatibility with modern web applications. Notable additions include the Navigation API, URLPattern, Trusted Types, Sanitizer API, and Prioritized Task Scheduling.

Firefox ESR 140.0 Release Notes:

New

  • Vertical Tabs: You can now keep more - or fewer - pinned tabs in view for quicker access to important windows. Just drag the divider to resize your pinned tabs section.
  • Custom Search Engines: Firefox now supports adding even more search engines. To add a custom engine, 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.
  • Firefox Extensions: Customize your toolbar with the option to remove the extensions shortcut, giving you more control over 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.
  • You can now unload tabs by right-clicking on a tab (or multiple selected tabs) and selecting "Unload Tab". This can speed up performance by reducing Firefox's memory and CPU usage.
  • Full-Page Translations now prioritizes 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.
  • Firefox builds in Arabic now come with a built-in Arabic dictionary for the Firefox spellchecker.
  • Address autofill enabled for users in Italy, Poland, and Austria.

Fixed

  • Various security fixes.

Changed

  • The Pocket toolbar icon, as well as the Pocket integrations on New Tab, have been removed per the service shutdown announcement.

Enterprise

Developer

  • Improved the search feature in the Inspector panel to help developers more effectively search the DOM of the current page. Sorting the results by the number of matching elements, support "pseudo" selector state, etc.

Web Platform

  • 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 styling arbitrary text ranges. Support for text-decoration is not included and is planned for an upcoming release.
  • Added support for 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.
  • 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.
  • 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 will now escape less-than (<) and greater-than (>) symbols when serializing HTML attributes, making certain mXSS attacks on websites more difficult.