Chrome's pop-up blocker is on, so why do ad tabs still open?

First, confirm the blocker is really on

1. Open Chrome, click the three-dot menu at the top right, then Settings.
2. Go to Privacy and security, then Site settings, then Pop-ups and redirects. The shortcut is chrome://settings/content/popups.
3. Under the default behaviour, choose Don't allow sites to send pop-ups or use redirects. This is Chrome's default.
4. Look at Allowed to send pop-ups and use redirects. If the problem site is listed there, click the three dots next to it and choose Block or Remove.

If you once clicked "Always allow pop-ups" on a site by accident, that exception wins over the default, so this check is worth doing.

What Chrome's blocker does block

• Windows a page opens on its own, for example when it loads or on a timer
• Pop-ups from sites you have put on the "Not allowed" list
• Some redirects that happen without any interaction

When it blocks something, Chrome shows a small "Pop-up blocked" icon in the address bar.

What it can't block

Browsers have to let real clicks open new tabs: that is how "open in new tab" links, share buttons and sign-in windows work. So Chrome allows a new tab if it opens as a direct result of a click or key press.

Ad scripts are designed around that rule. They wait for any click on the page, even on blank space or the Play button, and open their tab at that exact moment. To Chrome, it looks no different from a link you clicked. The same goes for invisible links laid over a video player, and for pages that open themselves in a new tab and then turn your current tab into an ad. We break down each trick in why clicking a website opens an ad in a new tab.

How to fill the gap

AdTabBlock is a free Chrome extension that adds the check Chrome's blocker doesn't make: did this tab come from what you clicked, or from a script riding on your click?

• A script opening a tab to a different website after your click: blocked
• An invisible link covering the page: disabled
• Your current tab being swapped for an ad: kept in place
• A link, thumbnail or button you actually clicked: opens normally
• Ctrl or Cmd + click, middle-click, right-click "Open link in new tab": always work
• Google, Apple and Microsoft sign-in, PayPal, Stripe and bank payment windows: always allowed

Check your setup

Open the test page with and without AdTabBlock. Without it, the tests open example.com in new tabs even though Chrome's blocker is on. With it, each test shows "Blocked".