The new version Firefox 147 It is now available on Mozilla servers, awaiting the official announcement, and Presents itself as the first major update to the free browser in 2026, with a clear focus on performance, internal organization, and security rather than flashy interface changes. Although the release is global, many of the new features are especially relevant for users of Europe and Spainwhere Linux and privacy concerns have a significant impact.
This is a version that combines profound engine improvementsOperating system-specific adjustments and new features designed for more convenient everyday use. From improved configuration file management in Linux to smoother video on systems with AMD GPUs, as well as new secure browsing options and minor productivity enhancements, the update addresses several areas at once.
New organization in Linux: full support of the XDG standard
After more than two decades of waiting, Firefox 147 finally incorporates compatibility with the XDG Base Directory specification from Freedesktop.org, a widely used standard in Linux desktops that defines where application configuration, data, and cache should be stored within the home directory.
Starting with this version, new installations or newly created profiles in Linux no longer dump everything into the folder ~/.mozilla and they switch to a more organized structure: the configuration files are saved in ~/.config/mozilla, the persistent data in ~/.local/share/mozilla and the cache moves to ~/.cache/mozillaThis makes it easier to have a system cleaner, more predictable, and easier to back up, something highly valued in professional environments and in public administrations that use Linux.
It is important to note that this new structure does not automatically alter the existing facilitiesExisting profiles will continue to use the classic location unless new ones are created. Even so, the change represents a step forward in aligning Firefox with the rest of the Linux desktop applications and simplifying the process. profile management in multi-user or remote work systems.
Visual improvements in GNOME and screen splitting
In addition to XDG support, Firefox 147 introduces a setting designed for those who use GNOME with the Mutter window managerThis is very common in distributions like Ubuntu, Fedora, and Debian, which are also widely used in Spain. Now, the browser synchronizes the window and rendering area size with the actual pixel grid when fractional scaling is applied.
This change causes the content to be displayed with greater clarity on screens with scaled to 125%, 150% or other intermediate values, without depending on the exact window size. In practice, text and images appear sharper, which is especially useful on high-resolution monitors, modern laptops, and the multi-monitor setups so common in remote work environments.
Smoother video: zero-copy on AMD GPUs and automatic Picture-in-Picture
In the multimedia section, Firefox 147 activates the call hardware video decoding "zero-copy" On AMD graphics cards, provided the system allows it. This technique avoids unnecessary data copying between the GPU and CPU during playback, reducing resource consumption and improving smoothness.
The goal is to bring AMD GPU performance closer to what was already seen in systems with Intel and NVIDIAThis is especially relevant for users who consume a lot of streaming video, video conferencing, or high-resolution content. On mid-range computers or laptops, this adjustment can result in a smoother experience and a slight improvement in battery life.
Another new feature visible to the user is the expansion of the function of Automatic Picture-in-Picture (PiP)Starting with Firefox 147, the browser can automatically open a small Picture-in-Picture (PiP) window when a video is playing in a tab that switches to the background. This feature, previously experimental in Firefox Labs, is now enabled by default.
If the behavior is not satisfactory, it can be adjusted from the settings, in the navigation section, where it is possible enable or disable the option to keep videos in Picture-in-Picture (PiP). when switching tabs. For those who frequently alternate between web-based work and video content (for example, online training or EU briefings), the feature makes it easier to follow the content without losing sight of it.
WebGPU on Apple Silicon and platform-specific improvements
Firefox 147 enables widespread support for WebGPU on Mac computers with Apple SiliconCovering all compatible macOS systems, WebGPU is the new graphics API for the web that allows you to take better advantage of modern GPU capabilities, which is key for 3D applications, online creative tools, browser games, and demanding interactive experiences.
With this move, users of Mac with M1, M2 and successor chips They can benefit from more efficient execution and enhanced graphics capabilities, opening the door to more advanced web applications without the need to install additional software. This support complements the improvements in Linux and the specific fixes for Windows, where a bug that prevented tab selection when the cursor was positioned at the top of some monitors has been resolved.
On Android, version 147 incorporates changes aimed at strengthening security against side channel attacks like Specterby enabling Site Isolation by default. This measure better isolates each website from the others, reducing the risk of information leaks between tabs or processes on mobile devices.
Safer browsing: Safe Browsing V5 and local network protection
Mozilla continues to fine-tune protection against malicious websites as it begins migrating from the protocol Safe Browsing V4 to V5 versionusing a local list-based mode. This change is part of the browser's strategy to maintain a balance between security and data control, an aspect of particular concern within the framework of the GDPR and European regulations.
In installations where Enhanced Tracking Protection is set to Strict, Firefox 147 also activates local network access restrictions when traffic originates from public sites. In practice, this means that certain pages will require explicit permission to use internal network resources, adding an extra layer of protection against potential attempts to scan home or corporate devices or services from the browser.
Pages that load faster: compression dictionaries and Brotli
Another relevant technical change is compatibility with compression dictionaries according to RFC 9842This specification allows for reducing the volume of data transferred when loading certain web pages. Some large sites already use this technology to shorten response sizes, which, combined with the widespread adoption of the Brotli algorithm, can significantly reduce loading times, especially on limited connections.
Firefox 147 also expands support for the compression and decompression streams API (CompressionStream y DecompressionStream) To Brotli formatThis opens the door for websites and online applications to manage their own compressed streams directly in the browser, improving efficiency in intensive data transfers, something increasingly common in cloud services and collaborative tools.
Changes to tabs, profiles, and user experience with Firefox 147
At the interface level, Firefox 147 reorganizes the tab options in the settings panel, dividing them into three groups: opening, interaction and closingThis redesign aims to make it easier for both new and regular users to locate settings related to tab behavior, from how they are opened to how they are managed when closed.
In addition, a new section appears on profiles in the General sectionThis feature acts as a management center for creating, editing, and separating browsing profiles. It's especially useful for those who want to distinguish between personal and work use, maintain separate sets of bookmarks or passwords, or share a single device among several family members without mixing browsing histories.
Firefox 147 also fixes minor interface bugs, such as problems with draggable buttons which ceased to be so if the drag was initiated exactly on the button, and other details that, although discreet, help to make daily use more consistent.
Experimental features in Firefox 147: lists, timers, and keyboard shortcuts
While the automatic Picture-in-Picture option is completely out of its experimental phase, version 147 incorporates a new feature in testing designed to improve the productivity on the Firefox homepageIt's called "lists and timer on the home screen," a feature that lets you create quick reminders, set a timer to stay focused, or receive alerts to take breaks.
Meanwhile, Mozilla is testing a new way to customize keyboard shortcuts, scheduled for full deployment in a later 147.x update. Enabling it from the address about:keyboardUsers can redefine hard-to-remember key combinations, avoid conflicts with other installed programs, or create their own shortcut configuration.
This flexibility is useful for advanced users, people with specific accessibility needs, or environments where several shortcut-intensive programs (such as code editors, design suites, or video conferencing applications) coexist with the browser. However, Mozilla warns that this is a experimental function And it is possible that errors or unexpected behaviors may still appear.
Updates for web developers and modern standards
Version 147 incorporates a significant set of new features for web developers and online application managers, with the aim of keeping the browser aligned with the latest standardsAmong the notable changes is the support for the Navigation APIwhich makes it easier to initiate, intercept, and manage navigation actions from JavaScript, which can simplify building single-page applications (SPAs) and complex dynamic experiences.
Compatibility with the Storage-Access-HeadersHTTP headers that allow servers to request access to unpartitioned cookies in contexts where privacy is stricter. This provides a clearer mechanism for managing which sites can retain certain types of information across domains, in line with the transparency requirements of European regulations.
In terms of design, Firefox 147 expands CSS support with the addition of units related to the base typography (rcap, rch, rex and ric), as well as support for anchor positioning (CSS anchor positioning) which makes it easy to "tie" visual elements to other page components. Furthermore, the pseudo-element ::marker gains the ability to use properties counter-* y quotesallowing for numbered lists and more flexible bullet styles.
The update also adds support for the service modules (module service workers)This improves interoperability with modern web applications that use ES modules and introduces the ability to import CSS stylesheets using JavaScript's module system along with import attributes. Together, these improvements facilitate more modular architectures and more organized code, which is especially appreciated in large projects or pan-European services that need to be maintained long-term.
Finally, it includes the Unicode 17 compatibility and new locales, which expands the repertoire of available characters and symbols and improves the browser's adaptation to different languages ​​and cultural contexts, including those of European countries with co-official languages ​​and specific alphabets.
HTTP/3 compatibility and improved language headers in Firefox 147
In the area of ​​network protocols, Firefox 147 fixes a bug that affected requests HTTP/3 with headers not encoded in UTF-8which could cause excessive wait times or drops to HTTP/2. With the applied fix, these requests should be handled more stably, benefiting services that have already switched to the new HTTP/3 standard to reduce latency.
Another relevant adjustment has to do with the treatment of the header Accept-LanguageUntil now, Firefox assigned lower priorities to secondary languages ​​(q=0,5), which caused some servers to misinterpret preferences and reject requests or serve content in an unwanted language. Starting with this version, the browser uses the same priority values ​​as other major browsers (q=0,9), improving compatibility.
For users in Spain and the rest of Europe, this means that language preferences (for example, es-ES, Catalan, Basque, Galician or English as a second language) should be better respected on multinational websites, avoiding unexpected language switches and reducing localization problems.
Firefox 147 download and availability
The final Firefox 147 binaries are now on Mozilla's servers for 64-bit, 32-bit, and ARM64 systems, and will soon be available for download from the official Firefox pageIn most installations, the update will be rolled out gradually and will appear automatically within a few hours, prompting you to restart your browser to complete.
In popular Linux distributions such as Ubuntu, Debian, Fedora or Linux MintThe new version will arrive through the usual channels: in Ubuntu it usually arrives as a Snap package with background updates, while in Linux Mint it is managed through its own update tool, which serves the browser packaged in Snap format. .debThose who prefer alternatives like Flatpak can install or update Firefox 147 from Flathub, or use the generic binary distributed by Mozilla.
For Windows and macOS users in Spain and the rest of the continent, the new version will appear in the system of Built-in automatic update from the browser. It is also possible to download the installer directly from the official website if you wish to force the upgrade to version 147 without waiting for the phased rollout.
With this release, Firefox 147 is shaping up to be an update focused on getting things in order: organizes data better in LinuxIt refines visual quality on modern screens, improves video performance, strengthens security with the new Safe Browsing and local network settings, and adds a number of advances in web standards and developer tools, all without major interface changes but with a noticeable impact on everyday use.
