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1.3 Firefox about:config: examples, Tutorial

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Modify entries examples, about:config section

Important note: before starting to modify about:config entries, it is highly recommended to create a copy of the prefs.js file. In case something happens, you may replace this untouched copy with the modified one. Prefs.js file is located in Firefox Profile folder.

Manipulate about:config entries:

  1. Examples:
    • boolean type: 1. browser.tabs.onTop; 2. view_source.syntax_highlight
    • string type: 1. browser.newtab.url
    • integer type: 1. browser.tabs.closeButtons

Video demonstration Firefox: about:config: examples

1.3 Firefox about:config: examples, Tutorial

min video details
00:01 open Firefox
00:06 open about:config page
00:11 BOOLEAN type
Example1: browser.tabs.onTop
00:15 browser on top: default value is 'true'
00:17 test1 ok: indeed, tab position is onTOP
00:18 test2 ok: right click, option 'Tabs on Top' ticked
00:20 untick option 'Tabs on Top' and note how the value of the preference 'browser.tabs.onTop' turned to false;
00:22 once we changed the value of 'browser.tabs.onTop', it became bold and the status is now: 'user set'
00:14 test1 ok: indeed, tab position is NOT onTOP
00:37 BOOLEAN type
Example2: view_source.syntax_highlight
00:38 searching for the another preference
00:41 view_source.syntax_highlight:
default value is 'true';
status: default; font-weight:normal
00:45 test ok: the page source syntax is highlighted
00:55 back to the preference, double click on it to change its value to: false
00:57 test ok: the page source syntax is NO LONGER highlighted
01:11 syntax highlighted versus syntax NOT highlighted
01:25 get new theme: this is an atipic example; if you want a new theme you will access the Add-ons Manager->Get Add-ons Tab->... but you can do it also by copy/pasting in browser the url found at this setting: 'extensions.getMoreThemesURL'
01:50 new theme installed
02:07 STRING type
Example1: browser.newtab.url
02:07 browser.newtab.url: default value is 'about:blank'
02:09 test ok: indeed, when opening new tab, a blank page displays
02:16 double click on it to display the pop-up window 'Enter string value';
in our case: http://google.com
02:24 test ok: indeed, @new tab, google.com page displays
02:49 INTEGER type
Example1: browser.tabs.closeButtons
02:49 browser.tabs.closeButtons: default value is 1
Note: we don't know what the value '1' represents
02:52 checking..: 1 means 'Display close buttons on all tabs (Default)
03:09 test ok: indeed, on all tabs we have a close button ('x' mark)
03:12 let's change the value of the preference 'browser.tabs.closeButtons' to 2
03:18 double click on the preference, type in the new value(2), hit OK button
03:19 test ok: no close button on tabs ('x' mark no longer displays)