The Custom JS scripts for Firefox 60+ and Thunderbird 68+Wiki contains a feature list (with screenshots).
Unlock custom CSS usage in Firefox 69 and newer
about:config
> toolkit.legacyUserProfileCustomizations.stylesheets
> true
Unlock custom CSS usage in Thunderbird 69 and newer
Settings/Options
> Advanced
> General
> Config Editor...
toolkit.legacyUserProfileCustomizations.stylesheets
> true
M1 is based on this project by nuchi: Method 1 - files in profile folder only (Fx60-71)https://github.com/nuchi/firefox-quantum-userchromejs
M1 stoped working in Firefox 72! XBL support got dropped.
From this projects
\method 1\
folder copy userChrome
folder and userChrome.css
file to \ PROFILENAME \chrome\
or add code from userChrome.css
file to an existing userChrome.css
file.Edit
userChrome\userChrome.xml
file to add custom scripts.
M2 is based on this project by ardiman: Method 2 - files in install and profile foldershttps://github.com/ardiman/userChrome.js
M2 is also based on the modified files by Endor8: https://github.com/Endor8/userChrome.js/
From this projects
\method 2\profile\
folder copy userChrome
folder and userChrome.js
file to \ PROFILENAME \chrome\
folder.From this projects
\method 2\firefox\
folder copy defaults
folder and config.js
file to Firefox main directory (where the Firefox executable is). Edit
userChrome.js
file to add custom scripts.With Firefox 62+ and Thunderbird 68+ an additional preference
pref("general.config.sandbox_enabled", false);
has to be set inside config-prefs.js
file. This is considered less secure by Mozilla and is only a temporary workaround, but at the moment it is the only way to run custom scripts using "method 2".
M3 is based on this project by xiaoxiaoflood: Method 3 - files in install and profile foldershttps://github.com/xiaoxiaoflood/firefox-scripts
From this projects
\method 3\profile\
folder copy utils
folder and userChrome.uc.js
file to \ PROFILENAME \chrome\
folder.From this projects
\method 3\firefox\
folder copy defaults
folder and config.js
file to Firefox/Thunderbird main directory (where the Firefox/Thunderbird executable is). Edit
userChrome.uc.js
file to add custom scripts or delete userChrome.uc.js
file and add scripts directly into /chrome/
folder.
Where to find Firefox Script/startup cache must be deleted after every change!
startupCache
folder?about:profiles > Local Directory > Open Folder
, close Firefox and delete all files in startupCache
folder.This is not the same 'profile' folder custom scripts and styles are stored in!
Where to find Thunderbird
startupCache
folder?Windows
C:\Users\ USERNAME \AppData\Local\Mozilla\Thunderbird\Profiles\ PROFILE FOLDER NAME \
Linux/macOS
Search for
startupCache
folder on your hard drive.More info about startup cache removal (in German): https://github.com/ardiman/userChrome.js/wiki/Skriptcache
More info about startup cache removal (in English [Google translation]): https://translate.googleusercontent.com/translate_c?act=url&depth=1&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&sp=nmt4&tl=en&u=https://github.com/ardiman/userChrome.js/wiki/Skriptcache
Where to find Firefox profile folder?
about:profiles > Root Directory > Open Folder
or about:support > Profile Folder > Open Folder
Windows Where to find Thunderbird profile folder?
C:\Users\ USERNAME \AppData\Roaming\Mozilla\Thunderbird\Profiles\ PROFILE FOLDER NAME \
Hidden files must be visible to see
AppData
folder. Alternatively open %APPDATA%\Mozilla\Firefox\Profiles\
from explorers location bar.Linux
/home/ username /.mozilla/thunderbird/ profile folder name /
Hidden files must be visible to see
.mozilla
folder.Mac OS X
~\Library\Mozilla\Thunderbird\Profiles\ PROFILE FOLDER NAME \
or~\Library\Application Support\Mozilla\Thunderbird\Profiles\ PROFILE FOLDER NAME \
\Users\ USERNAME \Library\Application\Support\Thunderbird\Profiles\
Script collection by ardiman: Script collectionshttps://github.com/ardiman/userChrome.js
Script collection by Endor8: https://github.com/Endor8/userChrome.js
Script collection by xiaoxiaoflood: https://github.com/xiaoxiaoflood/firefox-scripts/tree/master/chrome
Script collection by Patchonn: https://github.com/Patchonn/firefox-theme/tree/master/userChrome