Tab vs. Window

Use these links to test how Firefox loads this page with methods sites commonly used to launch a new window:

Link with target="_blank" — diverts to a new tab by default

Link with onclick="window.open()" (no features set) — diverts to a new tab by default

Link with onclick="window.open()" (width and height set to 800x600) — opens in a new window by default*

The Resolution Effect

Firefox 45 seems to be scaling the pop-up window based on the resolution of the page from which the new window is launched. To understand how this impacts your window size, you can experiment with zoom on this page before clicking the third link above.

*Preference Change

To force windows with features (third link) to launch in a new tab instead, you can make a change here:

1. In a new tab, type or paste about:config and press Enter/Return. Click the button promising to be careful.
2. In the filter box, type or paste neww and pause while the list is filtered.
3. There are three similarly named preferences for different scenarios, but the second one is the key change:
   1. browser.link.open_newwindow: 3 = divert new window to a new tab
   2. browser.link.open_newwindow.restriction: 0 = divert regular AND scripted windows with features
   3. browser.link.open_newwindow.override.external: -1 = follow browser.link.open_newwindow for external links

Cross-site: Open a window/tab Close that window/tab

Copyright © 2020 Jefferson Scher. All Rights Reserved.