Mozilla has announced, though it hasn't officially done so yet (it will do so later today), Firefox 151 as the new stable version Your browser's monthly update comes packed with visible changes and background tweaks. The focus is divided between a redesigned new tab page, new privacy options, improvements to the PDF viewer, and several features geared toward advanced users and developers.
Although this version mentioned the possible arrival of a native decoder for JPEG-XL imagesThis new feature has finally been delayed until Firefox 152 beta. Even so, Firefox 151 represents a significant step in the browser's evolution, especially for those who use the integrated VPN service, private browsing, the PDF viewer, or whose user profiles vary across different computers and operating systems.
New Firefox Home: This is how the new tab page changes in Firefox 151
One of the most visible changes is the redesign of the new tab page, which It will be called Firefox Home and adopts a more polished look. The change isn't revolutionary, but it introduces a design more consistent with the browser's upcoming redesign (known as Nova), with more rounded shapes and a somewhat lighter interface feel.
The most striking element is the central search bar, now with a "pill" design It's longer and has rounded corners. Furthermore, it no longer remains fixed when scrolling, which gives a little more visual space to the rest of the content as the user moves around the homepage.
The recommended stories are still there, but the button to follow topics has changed its appearance: it now looks like a plus sign icon located to the left of the section headerThe functionality, in essence, does not change: you can follow specific themes or adjust what type of content appears in that area.
For those who consider this section more noise than anything else, Firefox maintains the possibility of hide specific stories or block entire topicsIt's also possible to disable personalization based on browsing history. This personalization is enabled by default, but can be adjusted in the settings.
Personalization, shortcuts, and a new weather widget
Firefox Home also introduces a minor facelift to the Weather widget (available only in certain countries)which adapts to the new width of the search bar. The option to switch between simple and detailed views is gone: now a single box is displayed with the current temperature and the maximum and minimum temperatures.
Regarding shortcuts, Mozilla allows Show more rows of shortcuts on the homepageFrom the pencil icon, you can adjust these elements and reach up to a maximum of four rows, which can be useful for those who use Firefox as a starting point for their most common websites and services.
To complement this new visual approach, Firefox 151 incorporates a series of "new and eye-catching" wallpapers These options can be chosen to customize Firefox Home. The goal is to make better use of the space that was previously almost empty and to give options to those who want a more visually appealing home screen.
Design tweaks and first glimpses of the Nova redesign
Beyond the new tab, in this version we begin to see snippets of the Nova redesign in other parts of the browserThe settings page (accessible via about:preferences) becomes more compact, with elements better grouped and a somewhat denser design.
The internal search engine on the settings page also changes: The preferences search bar now occupies the entire width from the settings column, instead of being tucked away in a corner, making it easier to locate specific options when the user doesn't remember exactly which section they are in.
Experimental widgets available from Firefox Labs also benefit from minor visual tweaksAccording to Mozilla, they now integrate better into the overall design and no longer look so out of place compared to the rest of the browser's design.
Privacy: Quick button to clear private sessions and improved fingerprint protection
In the area of ​​privacy, Firefox 151 introduces a practical new feature in private browsing mode: a A specific button to delete the session without having to close the windowIt is a flame-shaped icon in the toolbar that allows you to delete cookies, history, and site data related to the open private session.
Clicking this button displays a confirmation message and, after accepting it, clears all data associated with that session and it leaves it ready as if a new private window had just been opened. The idea is reminiscent of DuckDuckGo's "Fire" function, which also uses a fire metaphor to reset everything, although Firefox hasn't incorporated a flashy animation.
Furthermore, Mozilla strengthens the protection against device fingerprinting Within the Enhanced Tracking Protection mode at the Standard level, the amount of system and browser information that websites can collect is limited, with the aim of making it more difficult to track users across different sites using passive identification techniques.
Firefox PDF Viewer 151: Merge files without leaving the browser
Firefox's native PDF viewer and editor continues to gain features, and in this version it receives one of the most useful: the ability to merge multiple PDF files into a single documentThis avoids having to resort to external applications or third-party web services for simple document merging tasks.
The process is quite straightforward: simply Open a PDF in your browser, open the sidebar, and click the plus icon.From there, you can select another PDF file in the system's file manager. Its content is appended to the end of the open document, and the user can reorder the pages or delete any they don't need.
Once everyone has the final document to their liking, all that remains is to... Export the combined PDF before closing the tab.For those who work with many documents, especially in administrative, academic, or legal environments, these types of integrated functions can save time and reduce reliance on additional programs.
Translations on your device: more direct access
Firefox recently introduced a dedicated page for managing translations. locally on the device itself, without sending the text to external servers.via the address about:translations. With Firefox 151, accessing this tool is simplified.
It is no longer necessary to remember or manually write the special address: The translations page can be opened from the browser's internal menu.Specifically, this can be found in the "More tools" section of the application menu. This feature may encourage more users to try local translations, a particularly important aspect for those who prioritize data protection.
Profile backups and synchronization between systems
Mozilla strengthens user profile management, a critical point when handling bookmarks, extensions, settings, and passwords across multiple computers. Firefox 151 enables the creation of local profile backups on Linux, an option that has been available in Windows for some versions now.
Furthermore, these backups now They can be restored across different platformsFor example, you can move a profile from macOS to Linux or vice versa, preserving themes, plugins, and other settings. This makes switching operating systems easier without losing your familiar browser environment, which is especially useful for users who frequently switch between different desktop environments.
macOS-specific improvements and region-specific adjustments
On macOS, Firefox 151 incorporates Universal Clipboard compatibilityThis allows for more seamless copying and pasting of content between devices within the Apple ecosystem, such as a Mac and an iPhone or iPad. It also introduces native menus integrated into the page itselfThis aims to make the experience more closely follow Apple's system design conventions.
On the other hand, in Europe there is a slight regional influence: The address auto-completion feature is enabled for users in the NetherlandsThis speeds up form completion for online purchases, service registrations, and digital transactions. It's expected that this feature will be gradually rolled out to other platforms, although Mozilla doesn't provide a specific timeline in the release notes for this version.
In the case of Windows, a adjustment in geolocation alertswith changes to how location requests are displayed to users. Although the basic behavior remains the same (requesting permission before sharing location), Mozilla is recalibrating the experience to better align with security and privacy expectations on this system.
New features for developers and web compatibility
With this API, developers can open a always-visible window containing arbitrary HTMLnot just video. This enables features such as custom controls in video calls, additional information panels, or floating tools that accompany the user while browsing other pages. Firefox thus aligns itself with browsers like Chrome, which incorporated this capability starting with versions such as 116.
Among the other development-oriented changes, the following stand out: Activating local network access restrictions for all usersThis is an important step in reducing security risks in web applications that might attempt to communicate with internal devices without the user's knowledge.
Support is also improved Fullscreen Keyboard Lock API, which now supports an argument in the requestFullscreen callallowing greater control over how and when the keyboard is locked in full-screen interfaces. Meanwhile, CSS rules @container expand their syntax and accept lists of query conditions and combined styles, something very useful for more flexible responsive designs.
In the hardware realm, Firefox 151 enables support for the Web Serial API in certain microcontrollers, including the Raspberry Pi PicoThis opens the door to web applications that interact directly with devices connected via serial port, an interesting possibility for educational, home automation, or rapid prototyping projects.
Firefox 151 Availability and Installation Options
Official Firefox 151.0 builds are available for direct download from Mozilla serversand soon on the project's official website. On Windows and macOS, the update arrives as an internal patch that is downloaded and applied from the browser itselfunless the user has explicitly disabled automatic updates. In Linux desktop environments, the situation varies somewhat more depending on the distribution and format chosen.
In Ubuntu, where Firefox is distributed by default in Snap format.The update to version 151 happens in the background, without user intervention, and is applied as soon as the browser restarts. Those who prefer the Flatpak format can install it from Flathub and update later using the command flatpak update or through graphical applications such as Bazaar, available in the Ubuntu 26.04 repositories.
For distributions like Linux Mint, the update is usually managed through the Mint Update tool or via the command line with aptIn any case, the release notes and the security section detail the included patches, which is relevant for system administrators and users who need to justify updates for regulatory compliance reasons.
With Firefox 151, Mozilla strengthens key parts of the browser without much fanfare: A more refined Firefox Home, clear privacy improvements, a more complete PDF viewer, and new APIs aimed at both end users and developers, this version feels like a solid interim step toward the future Nova redesign, with improvements that, while subtle, are practical for daily use and keep the browser well-positioned within the open-source ecosystem.
