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.

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.