HOWTO: Use a monospace font in GMail
2018-08-23 Update: It looks like Stylish has been barred from Chrome. Here’s an alternate extension.
2014-09-05 Update: Revised my Stylish answer
2012-01-09 Update: Note that pimp-your-chrome no longer works due to new Gmail style . . .
2011-04-06 Update: Added some additional options . . .
So, I have mixed feelings about GMail, but it is mostly good enough. However, if you are a system administrator, you find that the ability to render plaintext messages in a monospace font is really really important. Messages like this can get very annoying:
It is pretty lame that after these few years, GMail still has no feature to set your preferred font. But that doesn’t have to stop you! These days (2011) there are a few ways to achieve a fixed-width font in Gmail:
There are a few different ways to do this:
1) Use Stylish: Stylish is an extension available for most web browsers (but not Chrome!?) that allows users to easily plug in their own style overrides. I posted some instruction on Stack exchange.
2) Gmail Mono: An extension for Google Chrome. In 2018, this is what I use. Braindead simple:
https://chrome.google.com/webstore/detail/gmail-mono/cockeompoklmhodfbhbmnphfhpogmnbf
3) This last part no longer works with the new GMail style! Pimp your chrome: This is a Firefox hack that I committed in 2007. You’re probably happier with one of the above solutions, but you can jump down this rabbit hole if you like.
First, you’ll have to find your profile chrome.
On Windows, you can hit Start > Search, go into “More advanced options” and check:
- Search system folders
- Search hidden files and folders
- Search subfolders
Then, go ahead and search for your Local Hard Drives for all or part of a file name: chrome
Hopefully, you’ll find your chrome folder, which will be named something like:
C:Documents and SettingsdjhApplication DataMozillaFirefoxProfileszzxxzzxx.defaultchrome
On Macintosh, you can just type chrome into the search box in the Finder.
Select the folder with the newer time, which should have a path like:
~/Library/Application Support/Profiles/zzxxzzxx.default/chrome
Having located the chrome folder, open that folder up, and then edit the file userContent-example.css and add the following lines to the bottom of the file:
 /* GMail fixed-width font: see http://3cx.org/item/34 */  div.msg div.mb { font-family: monospace !important; font-size: 12px !important; }  textarea.tb { font-family: monospace !important; font-size: 12px !important; }  td.ct { font-family: monospace !important; font-size: 12px !important; } Â
Now, do “Save as …” in your editor, and set the file name to userContent.css. Then, restart Firefox, and things should look more awesome.
Since this little hack simply sets the default style for messages, HTML messages should render just as they always have.