This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Font Size

  • 3 replies
  • 1 has this problem
  • 1 view
  • Last reply by david

more options

How do I change the font size in Thunderbird? I am talking about the font size for everything. The titles, the menu titles, the messages. Everything is too small. Is there a way to see what has changed from default font settings or a way to reset back to default font sizes? Thank you

How do I change the font size in Thunderbird? I am talking about the font size for everything. The titles, the menu titles, the messages. Everything is too small. Is there a way to see what has changed from default font settings or a way to reset back to default font sizes? Thank you

Chosen solution

Okay, do this delicately. - close TB - make copy of prefs.js in profile in case you don't like results and need to restore original - start TB - go to tools>preferences>general and scroll down to config editor. - look for layout.css.devPixelsPerPx default is -1.0 try a minor change, such as 1.2 and see how that works. or maybe 2.0. This causes an immediate change. - if not what you want, repeat until pleased. If you made font too big to use TB, then

   close TB, and restore the copy of prefs.js and start over.
Read this answer in context 👍 0

All Replies (3)

more options

Chosen Solution

Okay, do this delicately. - close TB - make copy of prefs.js in profile in case you don't like results and need to restore original - start TB - go to tools>preferences>general and scroll down to config editor. - look for layout.css.devPixelsPerPx default is -1.0 try a minor change, such as 1.2 and see how that works. or maybe 2.0. This causes an immediate change. - if not what you want, repeat until pleased. If you made font too big to use TB, then

   close TB, and restore the copy of prefs.js and start over.
more options

THANK YOU, exactly what I needed!

more options

I was glad to help. You're very welcome.