Firefox Popup Settings: Opening Popups in a New Tab

By default, Firefox opens popup windows in a new browser window rather than a new tab. That’s usually fine, but it becomes a problem for anything that expects popups to land in a tab — a common example being automation tools like iMacros, which ignore separate popup windows entirely and only interact with content that opens in tabs.

Making the change

1. Open Firefox and type about:config into the address bar, then press Enter. You’ll get a warning about changing advanced settings — accept it to continue.
2. In the search box at the top of the about:config page, type:

browser.link.open_newwindow.restriction

3. The matching preference will appear in the list, with a default value of 2. Click the edit (pencil) icon next to it.
4. Change the value from 2 to 0, then confirm with the checkmark/tick icon.

What the values mean

This preference controls how window.open() calls are restricted:

• 0 — no restriction; popups that would normally open in a new window open in a new tab instead.
• 1 — only allow it for same-origin popups.
• 2 (default) — allow it for all popups, but treat popups requesting non-default window features (toolbars, specific sizing, etc.) as separate windows rather than tabs.

Close and restart Firefox after making the change. Popups that would previously have opened as separate windows should now open as new tabs instead.

Still Current in 2026

This preference is unchanged in current Firefox — confirmed directly against Mozilla’s own source repository, where browser.link.open_newwindow.restriction is still defined with the same default value of 2 and is still actively read by Firefox’s window-handling code. Current stable Firefox is version 153. No deprecation, removal, or default-value change has happened to this preference, so the about:config steps above work exactly as written on a fully up-to-date install.

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