# Waterfox 6.7.0

- Product: Waterfox (https://whatsnew.fyi/product/waterfox)
- Vendor: Waterfox
- Date: 2026-08-19
- Version: 6.7.0
- Original notes: https://github.com/BrowserWorks/waterfox/releases/tag/6.7.0
- Permalink: https://whatsnew.fyi/product/waterfox/releases/6.7.0
- Labels: Platforms: Desktop

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **changed** — Upgrade from Gecko ESR 140 to Gecko ESR 153 incorporating a year's worth of upstream engine, performance, and security improvements
- **added** — Nova browser style option, a new sharper Waterfox style with a brighter active tab line
- **changed** — Replace accent colour setting with twelve palettes ranging from Smoke and Ash to Sun, Spark, Flame, Lavender, Lagoon and Pine, each with light and dark variants
- **added** — Apply colour palettes to built-in pages such as Settings and other internal pages
- **changed** — Use Archivo font for headings across the interface
- **removed** — Remove the long list of small tweaks in the Look and Feel pane from Settings, keeping only seven options for Photon
- **changed** — Integrate tree-style tabs directly into the vertical tab strip instead of as a bundled extension
- **changed** — Save tree structure through the browser's own session store with existing trees and settings migrating on upgrade
- **changed** — Add settings under 'Tabs and Browsing' for how new tabs attach, what happens when closing a parent, double-click behaviour, branch auto-collapse, mute propagation and nesting depth
- **removed** — Remove large set of keyboard commands, custom CSS editor and API for other extensions from tree tabs integration
- **added** — Add dedicated settings panel for the built-in ad blocker
- **added** — Display status hero in ad blocker panel showing whether protection is active, paused, in partner mode or off for the site
- **added** — Show separate counts for ads, trackers and pop-ups with proportional bars in ad blocker panel
- **changed** — Move ad blocking to its own settings pane separate from Privacy and Security
- **added** — Inject anti-adblock and annoyance scriptlets before page scripts run
- **changed** — Increase redirect resources from 17 to 62 to reduce blocked requests breaking pages
- **added** — Add exception types allowing sites to be allowed broadly or narrowly, with exceptions added in private windows lasting only for the session
- **changed** — Update blocking engine to adblock-rust 0.13.2
- **added** — Add full support for legacy add-ons including reading 'install.rdf' manifests, running 'bootstrap.js', honouring 'chrome.manifest' overlay entries and supporting add-ons that require a restart
- **changed** — Rework preference handling so that disabling or uninstalling a legacy add-on no longer affects existing settings, browser defaults or locked preferences
- **added** — Allow installation of system add-ons without Mozilla signature and install companion app manifests for native messaging extensions on macOS and Linux
- **changed** — Redesign first-run onboarding as a single page with five steps: language selection, importing data, customising appearance, configuring tab layout, and accessing privacy settings
- **added** — Fully localise the first-run onboarding
- **removed** — Remove screens recommending extensions and displaying Android QR code from onboarding
- **changed** — Rewrite Firefox profile migrator to bring over bookmarks, history, form data, cookies and passwords

Waterfox 6.7 upgrades from Gecko ESR 140 to Gecko ESR 153. This release incorporates a year's worth of upstream engine, performance, and security improvements, and most of the Waterfox layer has been rebuilt to run natively on the new platform rather than being added to it.

If you have been following the beta series, a summary can be found below. Everything else below details what has changed since version 6.6.

##### Nova and the Colour System

The browser style can now be chosen from three options. Nova is a new, sharper Waterfox style with a brighter active tab line. Proton is a modern, standard design. Photon offers the classic Waterfox look with Lepton chrome refinements. New installations start with Nova. If you are upgrading, a one-time dialogue box will let you either keep your current style or switch to a different one; nothing will change until you make a choice.

The old accent colour setting, which offered three options, has been replaced with twelve palettes. These range from Smoke and Ash to Sun, Spark, Flame, Lavender, Lagoon and Pine. Each palette has light and dark variants that can be matched to your system theme. These palettes also apply to built-in pages, meaning that Settings and other internal pages will use your chosen colours.

Headings across the interface now use Archivo.

The long list of small tweaks in the Look and Feel pane is no longer in Settings. Seven options remain for Photon: transparency, auto-hide options, a close button on hover and a drag space. The rest still work for Photon via about:config. Please file a bug report for any toggle you rely on.

##### Tree Tabs

Waterfox 6.6 shipped tree-style tabs as a bundled extension — a fork of Tree Style Tab residing in its own sidebar panel. In version 6.7, tree tabs are integrated into the browser and built directly into the vertical tab strip.

- Tree tabs share code with vertical tabs, tab groups, the sidebar customisation panel and themes, meaning all four stay in sync.
- The tree structure is saved through the browser's own session store. Existing trees and settings migrate on upgrade.
- How far you drag a tab horizontally determines its nesting depth, and the whole subtree of a tab moves with it, including across windows.
- Settings under 'Tabs and Browsing' cover how new tabs attach, what happens when you close a parent, double-click behaviour, branch auto-collapse, mute propagation and nesting depth.

The native implementation is leaner than the old extension. It requires vertical tabs, whereas the old sidebar could sit next to a horizontal tab bar. A few extras did not carry over, including the large set of keyboard commands, the custom CSS editor and the API that other extensions could hook into. File a bug report if you relied on one of these features.

##### Ad Blocking

The built-in blocker, which has been included since version 6.6, now has its own panel in the Settings menu.

The panel now opens to show the status hero, which tells you at a glance whether protection is active, paused, in partner mode or off for this site. Below this, there are separate counts for ads, trackers and pop-ups with proportional bars, so you can see what a site was actually doing rather than just a single figure. The "see all" view lists everything that was blocked on the page, and the footer displays a running total. When protection is paused for a site, a badge appears on the toolbar button, so a paused site is obvious without opening the panel.

Beyond the panel:

- Ad blocking has moved to its own settings pane, separate from Privacy and Security. Filter lists, custom filters, custom lists and exceptions are all in one place.
- Anti-adblock and annoyance scriptlets are injected before page scripts run, fixing sites that previously overcame the blocker.
Redirect resources — the blank media and neutered scripts used as stand-ins for blocked requests — grow from 17 to 62, meaning fewer blocked requests will break the

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