Firefox Opens Links in New Windows Instead of Tabs? Fix It

Quick answer

Type about:config in the address bar, search for browser.link.open_newwindow, and set it to 3 (the default). That forces links that ask for a new window to use a new tab instead.

Why this happens

This error usually shows up after a Firefox update or when a browser extension (especially tab managers or pop-up blockers) messes with internal preferences. Sometimes you’ll accidentally toggle something in about:config while troubleshooting something else. I’ve seen it happen with older Firefox versions like 102 and 115, but it still pops up in the latest releases. The symptom is obvious: you click a link in Gmail, Slack, or a news site, and instead of a new tab, Firefox throws up a whole new window. Annoying, right? Let’s stomp it.

Step-by-step fix

1. Open Firefox and type about:config in the address bar. Hit Enter. Click “Accept the Risk and Continue” if warned.
2. In the search box, type browser.link.open_newwindow. You’ll see one preference listed.
3. Double-click the browser.link.open_newwindow entry. Change the number from 2 (open in new window) to 3 (open in new tab). Click OK.
4. Test it: open a site like Reddit, right-click a link, and choose “Open Link in New Tab” or just middle-click. Links should now stay in tabs.

If that doesn’t stick, check browser.link.open_newwindow.restriction. Set it to 0 (forces all new-window requests to tabs) or 2 (default—lets JavaScript decide). I recommend 0 if you’re still seeing windows.

Alternative fixes if the main one fails

Disable add-ons temporarily

Extensions like Tab Mix Plus, Tree Style Tab, or even some ad blockers can override tab behavior. Go to about:addons, click “Extensions” on the left, and disable all of them. Restart Firefox. If links now open in tabs, enable extensions one by one to find the culprit. I’ve seen Ghostery and uBlock Origin cause this in rare cases.

Reset Firefox without losing bookmarks

If nothing works, refresh Firefox. Go to about:support, click “Refresh Firefox…” in the top-right corner. This resets all settings, disables add-ons, but keeps bookmarks, passwords, and history. It’s the nuclear option but takes two minutes.

Check for malware

Sometimes browser hijackers (adware) change this behavior. Run a scan with Malwarebytes or the built-in Windows Defender. On Firefox’s side, go to about:preferences#privacy and click “Extensions and Themes” under “Custom” to see any suspicious add-ons. Delete anything you don’t remember installing.

Prevention tip

Once you’ve got tabs working, avoid installing tab management extensions unless you really need them. They often compete with Firefox’s built-in logic. If you do use one, check its settings for “open new windows in tabs” toggles. Also, after every major Firefox update (like version 120 or 130), quickly test a few links. Preferences can reset or change—it’s rare but happens. One last thing: don’t edit about:config randomly. I know it’s tempting, but it’s the fastest way to break things.

That’s it. No reinstalling, no third-party tools. Just a one-line config change or a quick add-on check. You’re welcome.