Popup Blocker by AdGuard

Popup Blocker is a userscript that blocks unwanted pop-up and pop-under windows in any browser that supports a userscript manager.

Unlike filter-list approaches, it wraps the browser's native APIs (window.open, .click(), .dispatchEvent(), etc.) with an additional verification layer. Only calls triggered by genuine user input are allowed through — automated pop-up scripts are blocked regardless of the domain or technique they use.

Repository: Development happens in the private repo AdGuardSoftwareLimited/ext-popup-blocker. A public mirror is available at AdguardTeam/PopupBlocker.

Key Features

• Advanced detection — blocks pop-ups at the API level, not via filter rules. Works even when pop-up scripts use WebRTC or rotate ad servers to bypass rule-based blockers.
• Restores expected click behavior — when a click would trigger a pop-up, the pop-up is blocked and the original click is still processed normally.
• Invisible to other scripts — the script cannot be detected by page scripts, which prevents circumvention attempts.
• Cross-browser — works in Chrome, Firefox, Edge, Safari, and any other browser that supports a userscript manager.

Installation

Popup Blocker is a .user.js file. To use it, first install a userscript manager in your browser:

• Tampermonkey (Chrome, Firefox, Edge, Safari)
• Violentmonkey (Chrome, Firefox, Edge)
• Greasemonkey (Firefox)
• AdGuard — go to Settings → Extensions → Add Extension and paste the script URL. Works in any browser AdGuard supports; the userscript comes pre-installed in AdGuard for Windows.

Then install Popup Blocker by clicking the link for your preferred channel:

Channel	URL
Release	https://userscripts.adtidy.org/release/popup-blocker/2.5/popupblocker.user.js
Beta	https://userscripts.adtidy.org/beta/popup-blocker/2.5/popupblocker.user.js

Your userscript manager will detect the .user.js file and prompt you to confirm installation.

How It Works

When a page attempts to open a pop-up or pop-under, Popup Blocker intercepts the call and checks whether it was triggered by a real user action (a click, keyboard event, etc.). If no qualifying user action preceded the call, the pop-up is blocked.

Popup Notifications

When a pop-up is blocked, a notification appears in the top-right corner of the page. From the notification you can:

• Show [URL] — allow the specific pop-up through once.
• Continue blocking — dismiss the notification and keep the pop-up blocked.
• Allow popups for [domain] — add the current site to the allowlist permanently.
• Don't show this message on [domain] — keep blocking pop-ups on this site but stop showing notifications.
• Manage preferences — open the options page.

Options Page

The options page lets you manage two site lists:

List	Effect
Allowed	Pop-ups are allowed through on these domains without restriction.
Silenced	Pop-ups are still blocked on these domains, but no notification is shown.

Open the options page for your channel:

Channel	URL
Release	https://popupblocker.adguard.com/release/v1
Beta	https://popupblocker.adguard.com/beta/v1

To add a domain, navigate to the options page, select the Allowed or Silenced section, enter the domain name, and click Add. To remove a domain, click the remove icon next to it.

Reporting a Bug

Submit bug reports and feature requests on the GitHub Issues page.

Contributing Translations

Help translate Popup Blocker into other languages via Crowdin.

Documentation

For build setup and contribution instructions, see DEVELOPMENT.md.

• Changelog
• LLM agent rules