AdGuard Browser Extension Release Notes

This release strengthens the foundation of the extension, focusing on what matters most — speed, reliability, and smooth performance in the new MV3 environment.

Faster filtering engine startup

The filtering engine, known as TSUrlFilter, powers the extension, blocking unwanted content and keeping pages clean. With this update, the engine starts up twice as fast, so the extension runs smoother, and remains stable even after background restarts.

Native :has support

Native :has support

To block and hide page elements, the engine uses CSS selectors — a fast and reliable way to keep pages clean. Previously, :has selectors were injected by the extension itself using extended CSS. Now, where supported, the engine uses the browser’s built-in :has selector instead. This makes filtering more stable and predictable, while also reducing the load on the system.

Improved HTML filtering

A single filtering method is usually not enough on its own. When ads or other elements try to blend in with page content, HTML filtering comes in handy. It works directly with the page’s structure to detect and remove such elements. This update improves HTML filtering and brings it in line with the latest CoreLibs version, offering more accurate handling of :contains rules.

Restored csp_report blocking

Restored csp_report blocking

Lastly, about our ongoing work with MV3. After moving to the new architecture, the blocking of csp_report requests stopped working, which could let websites collect additional data on blocked content and user activity. This update restores csp_report blocking in an MV3‑compatible way, bringing back the same level of protection and improving user privacy.

Changelog

Improvements

• Improved the readability of exported JSON files with settings by beautifying their structure
• Added support for the :has() pseudo-class as standard CSS when no other extended pseudo-classes are used in the selector, or when the #?# separator is explicitly specified
• Improved readability of filter update logs and added version information before and after updates
• Improved feature names and descriptions in Tracking protection (MV2)
• Improved filtering log performance by optimizing rule text retrieval

Fixes

• Repeated notifications when the dynamic rules limit is reached
• Network rules with the $important modifier are applied even when protection is disabled
• The Save button becomes active before the previous save operation is completed when editing User rules or Allowlist
• Some requests are blocked in Inverted allowlist even when no websites are added to Allowlist
• Filters are enabled after settings import when enabled-filters is empty
• The “Settings applied” notification appears before the settings are actually applied
• The “Preserve log” option does not retain all records in the Filtering log
• Tracking protection is disabled in MV3 extension when protection is paused
• $document blocking rules are applied even when a specific exception rule is present
• Blocked iframes are not collapsed in Firefox
• The extension throws an unexpected error when accessing [::]:8000
• Toggle does not work in User rules fullscreen mode
• Original rule text is displayed incorrectly in the Filtering log after rule conversion

TSUrlFilter (AdGuard Browser Extension filtering engine)

• Updated @adguard/tsurlfilter to v4.0.0
• Added full CSS selector syntax support in HTML filtering rules

TSWebExtension (Library wrapper for Browser API and TSUrlFilter)

• Updated @adguard/tswebextension to v4.0.0

Patch 3 for AdGuard Browser Extension v5.2 brings several improvements to the app’s usability and appearance.

The most significant change is that now you can update your custom filters seamlessly with just one click. This became challenging after moving to MV3, but the function is back.
Also, we have added an animated loading icon for the extension popup, so now you can easily check if the extension is up and running.

Changelog

Improvements

• Added the possibility to update custom filters in the MV3 version of the extension
• Added a new animated loading icon for the extension popup

Changelog

Improvements

• Added ability to update the extension with filters manually in MV3
• Decreased time period for temporary exceptions caused by clicking Proceed anyway on a blocking page from 40 minutes to 10 seconds
• Removed overflowing notification text in the options page
• Blocking page for requests blocked by
  $document
  rules in MV3
• Added support for Chrome’s User Scripts API that allows more reliable script injection in MV3
• Send last filter update time during issue reporting
• Added ability to exit editor by pressing the
  Escape
  keyboard button.
• Added сompatibility of
  $header
  modifier with
  $match-case
  and
  $third-party
  modifiers in MV2
• Added
  zip
  and
  crx
  artifacts for the extension builds
• Restored support for custom filters thanks to the User Scripts API
• Updated blocking pages in MV2 extension for Browsing Security and for web pages blocked by
  $document
  rules
• Improved accessibility for visually impaired users
• Removed AdGuard DNS filter and AdGuard Annoyances filter as deprecated
• Increased file size limit to 10MB for
  $replace
  rules in Firefox
• Updated
  @adguard/dnr-rulesets
  to v3.2.0
• Updated
  @adguard/filters-downloader
  to v2.4.2
• Updated
  @adguard/assistant
  to v4.3.75
• AGTree (A tool for working with adblock filter lists)
• Updated
  @adguard/agtree
  to v3.2.3
• AdGuard Logger (A tool for logging from AdGuard extensions)
• Updated
  @adguard/logger
  to v2.0.0
• Scriptlets (JavaScript enhancement for filtering rules)
• Updated
  @adguard/scriptlets
  to v2.2.10
• TSUrlFilter (AdGuard Browser Extension filtering engine)
• Updated
  @adguard/tsurlfilter
  to v3.4.6
• TSWebExtension (Library wrapper for Browser API and TSUrlFilter)
• Updated
  @adguard/tswebextension
  to v3.2.11

Fixes

• Cursor moves to the end when saving user rules
• Cannot maximize Filtering log in Firefox for Windows
• Unable to paste text into user rules input field on Android
• Invalid HTML rule selectors are breaking website loading
• Stealth mode’s Hide Referer from third parties option may break some websites
• Filtering log: Resizing the right panel selects its contents
• Types of the blocked requests are not displayed in the popup (Firefox for Android)
• Switching to the Statistics tab shifts the Actions and Statistics buttons (Edge for Android)
• Filtering log: Request details panel is automatically closed when loading a website in another window/tab
• Scriptlet rules are not displayed in the filtering log
• The filtering in Edge’s split screen doesn’t work
• Total blocked popup string translated incorrectly
• $replace rules may break some websites
• Missing space in the description of AdGuard German filter in the de locale
• OOM (Out of Memory) errors may occur when applying too many patches in a row in MV2
• File size limit too low for
  $replace
  rules in Firefox
• Attributes without value are not allowed for HTML filtering rules
• Firefox extension doesn’t launch on browser startup
• Wrong rule is displayed for pages blocked by
  $document
  rule in MV3
• Overflowing notification text in the options page