Firefox 157 Is Here With Nova: Mozilla’s Biggest Redesign in Years

Mozilla is giving Firefox a major visual makeover.

Firefox 157 brings Nova, a redesigned interface that changes the look and feel of the browser with more rounded elements, updated colors, new personalization options, and a more flexible approach to interface density.

Nova is the biggest part of this release, but Firefox 157 isn’t only about appearance. Mozilla has also improved video calling with hardware-accelerated AV1 decoding, fixed several media playback problems, removed Amazon from the built-in search engine list, and expanded Firefox Suggest to additional countries.

Firefox 157 is scheduled for its stable release on September 29, 2026, although the final binaries are already available on Mozilla’s servers ahead of the wider automatic rollout. Mozilla has also recently moved Firefox to a two-week release cycle, making major changes arrive more frequently.

Here’s what’s new in Firefox 157.

Firefox 157’s biggest change is the new Nova interface

Mozilla has been working on Nova for months, describing the project as a major effort to modernize Firefox’s design system.

The redesign changes much of the browser chrome surrounding your webpages.

The most obvious differences include:

• More rounded tabs
• A redesigned address bar
• Updated menus and controls
• Refreshed icons
• New colors and visual treatments
• A redesigned sidebar
• Additional customization options
• More control over interface spacing

Mozilla describes Nova as an effort to make Firefox feel cleaner, warmer, faster, and more adaptable, while retaining the browser’s existing identity.

The change is significant, but Mozilla isn’t replacing Firefox with an entirely different browser. The familiar navigation controls, tabs, address bar, extensions, and settings remain in place.

Firefox’s new design is more customizable

Nova also expands the visual customization available to Firefox users.

The updated interface supports different color treatments and themes, including light and dark appearances. Firefox’s New Tab experience also receives new personalization options, including additional background imagery.

That means users who prefer a more colorful browser can customize Nova’s appearance, while users who want a simpler interface can stick with a more traditional look.

Firefox 157 brings back Compact mode

One of the more useful changes for power users is the return of an official Compact interface density option.

Firefox 157 adds Window density to the browser’s Appearance settings. Users can choose from four options:

The Compact option is particularly useful if you regularly work with many tabs or use a laptop with a relatively small display.

Instead of using browser configuration hacks to reduce Firefox’s interface size, users can now control the setting directly from the normal Appearance preferences. Mozilla’s support documentation specifically lists Window density and Compact mode for Firefox 157.

Firefox 157 improves video calls with hardware AV1 decoding

Firefox 157 also includes an important technical improvement that won’t necessarily change the browser’s appearance but could make a difference during video calls.

Firefox can now use hardware AV1 decoding for WebRTC video calls on compatible systems.

Previously, Firefox relied on software decoding for AV1 WebRTC video. With Firefox 157, supported hardware can take over that workload instead.

Hardware decoding can reduce the amount of work performed by the CPU and can be particularly useful on laptops, where reducing CPU activity can also help with power consumption and thermals.

The feature depends on hardware and driver support, so not every computer will benefit from it.

HDR video and playback synchronization get fixes

Firefox 157 also contains several video-related fixes.

Mozilla has addressed an issue where certain HDR video content on Windows could appear washed out or gray instead of displaying the expected image.

The update also improves audio and video synchronization when repeatedly changing playback speed.

That can be noticeable on sites such as YouTube when switching between speeds such as 1x, 1.25x, 1.5x, and 2x multiple times during playback.

These aren’t headline features, but they’re the sort of fixes that can make everyday media playback more reliable.

Amazon is no longer a built-in Firefox search engine

Firefox 157 also changes the list of search engines available by default.

Amazon has been removed from Firefox’s built-in search engine selection.

If you still want to search Amazon directly from Firefox’s search settings, you can add it manually rather than using one of the default search providers.

The change is relatively minor, but it means users upgrading from previous versions may notice that Amazon is no longer present in the built-in list.

Firefox Suggest expands to more countries

Mozilla is also continuing the international rollout of Firefox Suggest.

The feature can provide suggestions and localized results directly in Firefox’s address bar. Depending on the market and configuration, suggestions can also include sponsored content.

With Firefox 157, Firefox Suggest is expanding across additional European markets, including:

• Austria
• Belgium
• Czech Republic
• Denmark
• Finland
• Hungary
• Ireland
• Luxembourg
• Netherlands
• Norway
• Poland
• Portugal
• Slovakia
• Spain
• Sweden
• Switzerland

Mozilla has been gradually expanding the feature geographically rather than enabling the same experience everywhere at once.

Users who don’t want sponsored suggestions can manage Firefox’s search and suggestion settings.

Firefox 157 also fixes several annoying bugs

The release includes a collection of smaller fixes that are easier to appreciate when you run into the problems they address.

Among the fixes reported for Firefox 157 are improvements involving:

HDR video on Windows

Some 8-bit HDR video could previously look dull or gray. Firefox 157 includes fixes aimed at improving the rendering of this content.

Video and audio synchronization

Changing video playback speed repeatedly could cause audio and video to drift out of sync. The update improves synchronization when changing playback rates.

Address bar suggestions

Firefox could sometimes perform a search instead of opening the selected suggestion when a page was still loading, particularly immediately after Firefox started.

Vertical tabs in fullscreen

The sidebar containing vertical tabs could fail to reappear when moving the pointer toward the edge of the screen while Firefox was in fullscreen mode.

Windows fullscreen video

On Windows, the taskbar could sometimes remain visible over fullscreen video. Firefox 157 addresses this behavior.

These fixes complement the larger Nova redesign and media improvements included in the release.

Firefox is now moving to a two-week release schedule

Firefox 157 is also notable because it arrives during Mozilla’s transition to a faster release cadence.

Mozilla changed Firefox from a roughly four-week release cycle to a two-week cycle beginning with Firefox 155. The goal is to deliver completed features and bug fixes more frequently and make releases more predictable.

That means Firefox users should expect version numbers to increase more quickly than they did in previous years.

For users, the practical benefit is that completed fixes and improvements don’t necessarily have to wait as long for a major release.

Firefox 157 also includes developer changes

Although most users will notice Nova first, Firefox 157 includes changes for web developers as well.

The release adds support for the CSS at-rule() function inside @supports, allowing websites to test whether a browser supports particular CSS at-rules.

Firefox 157 also adds support for the WebGPU TRANSIENT_ATTACHMENT texture usage type. Mozilla says this can allow memory-efficient attachments to remain in tile memory during a render pass, potentially reducing VRAM traffic and avoiding some texture allocations.

These changes won’t matter to most Firefox users directly, but they expand the capabilities available to websites and web applications.

Firefox 157 release date: when can you download it?

Firefox 157 is scheduled to reach the stable channel on September 29, 2026.

Mozilla’s release tracking confirms that the desktop and Android release was scheduled for September 29, following the final release candidate.

However, the Firefox 157.0 binaries are already available from Mozilla’s release servers, so users who don’t want to wait for the automatic rollout can obtain the release directly.

For most users, the easiest option is simply to let Firefox update itself.

How to manually check for Firefox 157

Open Firefox and:

1. Click the ☰ menu.
2. Open Help.
3. Select About Firefox.
4. Firefox will check for available updates.
5. Restart the browser if an update is downloaded.

Because Mozilla is moving to a two-week release cycle, the exact timing of the update notification can vary slightly depending on the platform and rollout.

Should you update to Firefox 157?

If you already use Firefox, Firefox 157 is a particularly noticeable update because Nova changes the browser’s interface, not just its underlying engine.

The new design won’t appeal to everyone, but Mozilla has included customization options such as different themes and Window density, including the Compact mode for users who prefer a denser interface.

The technical improvements are also useful. Hardware AV1 decoding can improve WebRTC video calls on compatible hardware, while the HDR and playback synchronization fixes address real-world media problems.

And because Firefox has now moved to a two-week release schedule, this version is also part of a broader change in how quickly Mozilla intends to deliver updates.

Final thoughts

Firefox 157 is much more than another routine browser update.

Nova gives Firefox one of its most substantial visual changes in years, while the return of Compact mode gives users more control over how much screen space the browser interface consumes.

Under the hood, hardware AV1 decoding for WebRTC, improved video playback, HDR fixes, search-engine changes, and a collection of smaller fixes make the release more than a cosmetic refresh.

If you’ve been using Firefox for years, the first thing you’ll notice after installing version 157 is Nova. After that, the smaller improvements are what make the update more interesting.