Mozilla Firefox 157.0 / 158.0 Beta 3

Firefox 157 brings the biggest visual refresh in years, a redesign Mozilla built under the name Project Nova.

Underneath the new look it is the same browser, built on Mozilla's own Gecko engine rather than the Chromium code behind Chrome, Edge, Brave and Opera.

Your bookmarks, passwords, add-ons and settings carry over as they are when it updates.

What's New in Firefox 157

• The Nova redesign. Tabs, menus, the address bar, the sidebar and pop-up panels are rounder, with refreshed icons and tidier spacing.
• New built-in themes. Each one comes in a light and a dark version.
• Compact mode is back. It tightens the toolbars and tabs, and an Auto setting switches it on for small screens and split-screen layouts.
• AV1 video calls. Web video calls can now use hardware AV1 decoding on PCs whose graphics chip supports it.
• The Tab key goes straight to the address bar. The search engine button is still there, one Shift+Tab away.
• Amazon is no longer a built-in search engine. You can still add it back as a custom one.
• Local address bar suggestions reach 16 European countries. They can be switched off in the Firefox Suggest settings.

Fixes Worth Knowing About

• HDR videos stored in 8-bit colour no longer look dull and grey on Windows.
• The Windows taskbar no longer sits on top of fullscreen videos.
• Sound and picture stay in sync after you change the playback speed several times.
• Picking an address bar suggestion while a page is loading now opens that suggestion instead of searching for what you typed.
• The vertical tabs sidebar reappears in fullscreen when you move the pointer to the screen edge.

The release also carries Mozilla's usual batch of security fixes, which is reason enough to update even if you never notice the new look.

Don't Like the New Look?

If the new spacing feels roomy, turn on compact mode first - it wins back most of the height the rounder design uses.

Mozilla has also left a switch in about:config that turns the Nova design off for now. Expect it to be temporary, so it is worth giving the new layout a week before reaching for it.

Why Firefox Is Different From Chrome and Edge

Enhanced Tracking Protection is on from the first launch. It blocks social media trackers, cross-site tracking cookies, cryptominers and known fingerprinting scripts without a single extension, and the shield icon in the address bar shows what it stopped on each page.

Page translation runs on your own computer. Firefox downloads a language model once and translates locally, so the text of the page is not sent off to a translation server.

Firefox is free, and Mozilla earns its money mainly from search deals and sponsored suggestions. You can switch the sponsored ones off in Settings under Search.

System Requirements

On Windows, Firefox needs Windows 10 or 11, with 32-bit, 64-bit and ARM builds, 2GB of RAM for the 64-bit version and about 500MB of disk space. Windows 7 and 8.1 cannot run current versions.

Mozilla also builds Firefox for macOS 10.15 or later and for 64-bit Linux. 32-bit Linux lost support back in Firefox 145, and the ESR 140 builds that covered it reach end of life with this release.

Who Should Look Elsewhere

If a site you rely on says your browser is not supported, or you depend on an extension that only exists for Chrome, a Chromium browser saves you the hassle. Brave Browser blocks ads and trackers by default and runs Chrome extensions.

If you like Firefox but want stricter defaults, LibreWolf is Firefox with the telemetry stripped out and the privacy settings locked down. For real anonymity, Tor Browser routes every connection through the Tor network.

Want more from the interface? Zen Browser rebuilds Firefox around vertical tabs and workspaces, and Floorp Browser adds web panels and deep layout tweaks.

Other Browsers Worth a Look

Google Chrome still has the widest site compatibility, though it collects far more data about you. Microsoft Edge is already on every Windows PC and builds in Copilot.

Vivaldi Browser packs a mail client, a calendar and endless layout options into one app. The full lineup sits in our web browsers category.

Handy Companions for Firefox

Free Download Manager hooks into Firefox to speed up and resume large downloads. For saving videos from streaming sites, yt-dlp handles hundreds of them from the command line.

Anything you download plays in VLC Media Player without extra setup. If you would rather use the players already on Windows, the K-Lite Codec Pack adds the codecs they are missing.

Quick questions

Download Mozilla Firefox 157.0 and see how the new look suits you, or tell us how you got on if you have used it before.