Make Firefox automatically set zoom level for new webpages

When Firefox goes to a new webpage I don't want it at 100% zoom but at a different percentage that I specify, and I want it to always use this zoom for all pages that it goes to. How can I do that?

The Firefox addon NoSquint allows you to adjust the text-only and full-page (both text and images) zoom levels as well as color settings both globally (for all sites) and per site.

This is user configurable from Firefox, without the need for any add-ons.

1. In the address line, type: about:config

2. Scroll down or search for the preference name: browser.zoom.siteSpecific

3. Double-click to change the value to false

Now your zoom settings will carry over from site to site.

The default zoom in Firefox can be reset to any value for all webpages without installing an extension.

1. In the Firefox address bar type: about:config

2. Search for this preference: layout.css.devPixelsPerPx

3. Replace the default value of -1.0 with the new percentage zoom. For example, if you want to change the default zoom from the default value of 100% to 125%, then change the value of layout.css.devPixelsPerPx to 1.25

If you are also using Chrome web browser then the default zoom level can be easily changed from the settings ( 3 vertical dots icon ⋮ ) in the upper right corner of Chrome. For a better browsing experience set the same default zoom for both Firefox and Chrome.

This was tested on the latest version of Firefox 57 (a.k.a. Firefox Quantum) and Chrome 62, and it also works on Firefox 52 Extended Support Release (ESR).