Popup Blocker by AdGuard 
Summary:
Popup Blocker by AdGuard is a userscript that blocks all unwanted pop-up windows in different browsers.
Key features:
- Cross-browser support
Works in Chrome, Firefox, Edge, Safari, IE10+ etc, basically in any browser that supports userscript managers. Exceptions are some of the oldest browsers that do not support the API we use, the script may not be fully functional there.
- Advanced pop-up detection
Popup Blocker doesn't apply the filtering rules approach to pop-up detection. Instead, it adds an additional layer on top of browser's native APIs that are used to create pop-ups. This way, these APIs can only be called when caused by a manual input, and not by pop-up/pop-under scripts. That allows to block pop-ups even on websites that try to bypass regular ad blockers by using WebRTC or varying the ad servers.
- Restores the expected click behavior
Self-explanatory but important: if a click would cause a pop-up to show, not only the pop-up is blocked, but also the initial click is processed as it would be without the pop-up.
- Invisible to other scripts
Other scripts on the page can not detect that Popup Blocker is being used, other than by actually trying to open a pop-up. This prevents any possible circumvention of Popup Blocker.
Installation
Current release version (2.1.10): https://cdn.adguard.com/public/Userscripts/AdguardPopupBlocker/2.1/popupblocker.user.js
Curent beta version (2.1.10): https://cdn.adguard.com/public/Userscripts/Beta/AdguardPopupBlocker/2.1/popupblocker.user.js
All versions: https://github.com/AdguardTeam/PopupBlocker/releases
Popup Blocker is being developed by the same team that develops AdGuard, and AdGuard for Windows can serve as a userscript manager. If you are an AdGuard user, go to Settings – Extensions – Add Extension and enter the desired Popup Blocker .js file URL there. This way you can use it in literally any browser.
On the other hand, Popup Blocker is an independent project, you can use it with any other userscript manager like Greasemonkey, Tampermonkey or Violentmonkey. Make sure one of them is installed in your browser to be able to use the Popup Blocker (just enter the script URL into the address bar, it will be automatically detected by the manager).
Options page
From userscript version 2.5.0 and higher, you can manage a list of whitelisted domains and silenced domain on a dedicated options page.
Reporting a bug
To report a bug, go to this page and create a new issue.
Translation
You can help us with translating Popup Blocker into other languages! Our project on OneSky is open for public contributions.
Development build
Built automatically on every new commit: https://popupblocker.adguard.com/popupblocker.user.js
Development builds have logging enabled and overrides significantly more browser apis to introspect behavior of popup/popunder script. It is not suitable for normal usage.
Unit test for dev build is here.
How to build
Install gulp and ts-node globally by running:
npm install -g gulp ts-node
Install local dependencies by runnning:
yarn install
To build, run:
$ gulp <channel>-<target>[-[un]minified]
or in a minimist style:
gulp build --channel=<channel> --target=<target> --minify=(boolean) --use_adg_domain
Available channels are: dev, beta, release
Available targets are: userscript, chrome, webext
minify option will override default minification settings for channel.
use_adg_domain option will make userscript builds to use urls in adguard.com domain as urls of @resource meta tags.
Developement builds are not minified, and will print logs into the browser console.
Beta and release builds will be minified and have all logging codes stripped out. For minified builds, ensure that you have Java installed and have necessary environment variables.
How to test
An easy way to test the script is to visit http://code.ptcong.com/better-js-popunder-script/
Just click anywhere on that page to get a popunder, or use specific links to get popup/popunder/tabup/etc.
Expected behavior: new windows get blocked with a notification in the top right corner.