Since a update a few weeks ago Firefox doesn't seem to keep settings done in about:config. I noticed this for example because I use a changed dpi setting


After an update this was reset to -1.0. Changing this to 1.5 again however works only temporarily. After restarting Firefox the setting is gone.

What may be wrong here and how can I fix it?

  • I was using the web interface. – student May 24 '18 at 21:44

You can edit the prefs.js file in the Firefox profile folder with a plain text editor like Notepad and remove the line with the layout.css.devPixelsPerPx pref or change the value to 1.0

user_pref("layout.css.devPixelsPerPx", "1.0"); 

From https://support.mozilla.org/en-US/questions/964888

  • Thanks, I manually added the key to my user.js and now it seems to work after a reboot. Maybe you could include this information explicitly into your answer then I can accept it. – student May 24 '18 at 20:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.