Firefox users may soon be able to set the global zoom level for all Web sites in a browser. Currently, users can only rely on third-party browser extensions to set up this function.
Firefox Web browser itself supports multiple zoom function. Users can zoom level will be applied to different sites, hold down the Ctrl key and using the mouse wheel can be. In addition, the browser will remember the zoom level.
Site-specific zoom feature is introduced in 2009, Firefox 3, you can disable it in the Advanced Configuration. 2016, Firefox 51 introduces another zoom feature, the browser will be highlighted if the zoom is not set as the default value in the address bar.
Now, Mozilla plans to introduce new configuration options to set the default zoom level in Firefox 73 globally. Users can customize the zoom level, apply to all sites, and set as the default. Meanwhile, Mozilla also wants to introduce an option to limit the scale text only content on the page.
Starting Firefox 73 release, users can open the browser's preferences to set global zoom level, this feature has been available in the Firefox Nightly. Load about the address bar of your browser: preferences or select Menu> Settings> General can be. Scroll down the page to the new "Zoom" group setting, you can find to change the default zoom level of between 30% and 300% of the options in them.
After setting a global scale, the opened web page does not need to be reloaded, the zoom level will be automatically applied to them. Only want to zoom text Firefox users can select the "Zoom Text Only" on the preference page (zoom text only) box to enable the feature.
Since Firefox has a site-specific zoom level function, so you can still change the zoom level of a particular site, and Firefox will remember the zoom level for the entire session.
Firefox 73 is expected in 2020 February 11 officially released.
Source: https://www.ghacks.net/2019/12/26/firefox-73-gets-an-ui-option-to-set-a-global-zoom-level/