Firefox 153 Released with PDF Modification and HDR Video Support: Defines the New ESR
Mozilla has released the new Firefox 153, a significant update that marks the debut of the new Extended Support Release (ESR) branch intended to serve as a reference for the next twelve months. Among the visible impacts for daily use is the enhancement of integrated tools for reading and managing PDF files, alongside support for HDR video playback on Windows systems where the mode is enabled at the operating system level.
The built-in PDF editor gains the ability to merge multiple documents into a single file and to insert images onto pages, reducing reliance on external software. In parallel, the development team has begun the preview phase for Native Containers, a long-standing feature previously tied to installing the separate Multi-Account Containers extension. This solution allows for the isolation of browsing sessions, cookies, and tracking within distinct tabs (dedicated to work, shopping, finance, or personal life) in the same browser. Container management occurs directly from system settings or via contextual menus using customizable names, colors, and icons.
Mozilla Releases Firefox 153: What Changes
Under the hood, the introduction of support for Qualified Web Authentication Certificates (QWAC) and various structural refinements are notable. The strategic value of this release lies mainly in its framing as an ESR version. This package indeed defines the technical specifications that will be inherited for an entire year by major Linux distributions such as Debian, Red Hat Enterprise Linux (RHEL), Kali, Tails, SUSE Linux Enterprise, and Slackware, which integrate the ESR variant as the default system browser.
The ESR framework serves as the starting point for derivative projects like Waterfox and KaiOS, as well as representing the operational standard for numerous enterprises. Many independent software vendors (ISVs) and SaaS platforms certify the compatibility of their services exclusively on this branch with guaranteed stability. The automatic distribution of ESR 153 for managed channels will begin in two months, during which ESR 140 will continue receiving security updates; thus, immediate adoption of release 153 requires manual installation.
The support architecture maintains an active channel for those operating on desktop platforms no longer updated by respective manufacturers. Users of Windows 7, Windows 8, and 8.1, along with those using dated editions of macOS, will refer to the ESR 115 branch, whose coverage is confirmed until March 2027. Mozilla calls attention to the dangers associated with using an updated browser on operating systems lacking Microsoft security patches since January 2023, noting that maintaining code for obsolete environments incurs high technical costs and vulnerabilities for the user. The updated package can be downloaded from the official Firefox website.