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How do I set the general zoom level programmatically
When I use Firefox on the external monitor, I set the zoom level to 150%. When I leave home a take my laptop with me, I set the zoom level to 100% to use with a smaller screen.
I want to automate setting the zoom level.
Is there a way to programmatically set the zoom level from a script? Does Firefox expose such an API / command-line tool?
Thanks!
Saafara biñ tànn
Hi Pierre, this is a tough one. The default zoom level is stored in a database with site-specific zoom levels, and there's no preference you can set directly to modify that value.
You definitely can do it with a script you run manually in the Browser Console window, which has an optional global command line. The Options page is probably faster...
/* Default Zoom Level Setter for the Browser Console (2020-08-12) NOTE: BEFORE YOU CAN RUN THIS SCRIPT, ONE-TIME SETUP: Type or paste about:config into the address bar and press Enter Click the button promising to be careful In the search box type devt and pause while Firefox filters the list If devtools.chrome.enabled is false, double-click it to toggle to true Paste this entire script into the command line at the bottom of the Browser Console (Windows/Linux: Ctrl+Shift+j; Mac: Command+Shift+j). Then press Enter to run it. Firefox should flip to an open window and ask what percentage you want. Ref. https://searchfox.org/mozilla-release/source/browser/components/preferences/main.js#1166 */ var newpct = window.prompt('New default zoom percentage (e.g., 100, 120, ...)?', '150'); if (newpct){ let cps2 = Cc["@mozilla.org/content-pref/service;1"].getService(Ci.nsIContentPrefService2); let nonPrivateLoadContext = Cu.createLoadContext(); let win = window.browsingContext.topChromeWindow; cps2.setGlobal(win.FullZoom.name, parseFloat((newpct / 100).toFixed(2)), nonPrivateLoadContext); }Jàng tontu lii ci fi mu bokk 👍 1
All Replies (4)
Saafara yiñ Tànn
Hi Pierre, this is a tough one. The default zoom level is stored in a database with site-specific zoom levels, and there's no preference you can set directly to modify that value.
You definitely can do it with a script you run manually in the Browser Console window, which has an optional global command line. The Options page is probably faster...
/* Default Zoom Level Setter for the Browser Console (2020-08-12) NOTE: BEFORE YOU CAN RUN THIS SCRIPT, ONE-TIME SETUP: Type or paste about:config into the address bar and press Enter Click the button promising to be careful In the search box type devt and pause while Firefox filters the list If devtools.chrome.enabled is false, double-click it to toggle to true Paste this entire script into the command line at the bottom of the Browser Console (Windows/Linux: Ctrl+Shift+j; Mac: Command+Shift+j). Then press Enter to run it. Firefox should flip to an open window and ask what percentage you want. Ref. https://searchfox.org/mozilla-release/source/browser/components/preferences/main.js#1166 */ var newpct = window.prompt('New default zoom percentage (e.g., 100, 120, ...)?', '150'); if (newpct){ let cps2 = Cc["@mozilla.org/content-pref/service;1"].getService(Ci.nsIContentPrefService2); let nonPrivateLoadContext = Cu.createLoadContext(); let win = window.browsingContext.topChromeWindow; cps2.setGlobal(win.FullZoom.name, parseFloat((newpct / 100).toFixed(2)), nonPrivateLoadContext); }
@jscher2000 There is now a "Default zoom" option in Preferences->Zoom->Default zoom . I can't seem to find the about:config option to set it. Any ideas?
rathann said
@jscher2000 There is now a "Default zoom" option in Preferences->Zoom->Default zoom . I can't seem to find the about:config option to set it. Any ideas?
It is not stored in about:config. It is stored in the content-prefs.sqlite database along with site-specific zoom levels (it is associated with a group with a null name).
(You can use this query in a SQLite viewer to list out the zoom levels in the database: SELECT name, value FROM 'prefs' left outer join 'groups' on prefs.groupID = groups.id WHERE settingID = 1 )
You can consider two use separate profiles each with their own default zoom setting and use Sync to keep both profiles synchronized.