How can I change the font size of a Thunderbird thread list on a Mac?

Question

How do I change the font size of a Thunderbird thread list on a Mac?

I don't see any settings in the preferences.

Set it up 11 intead and it will display better – Jan 26 '11 at 18:31 — , Jan 26 '11 at 18:31

qingu · Answer 1 · 2023-09-28T17:31:55.667

Daniel's answer is correct. You have to extend userChrome.css in the ~/Library/Thunderbird/Profiles/[yourProfileName]/chrome/ folder. Here is the CSS code that will fix the spacing as well:

/* Set default namespace to XUL */
@namespace
url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
/* Set font size in folder pane */
#folderTree >treechildren::-moz-tree-cell-text {
    font-size: 12pt !important;
}
/* Set font size in thread pane */
#threadTree >treechildren::-moz-tree-cell-text {
    font-size: 12pt !important;
}
/* Set height for cells in folder pane */
#folderTree >treechildren::-moz-tree-row {
   height: 25px !important;
}
/* Set height for cells in thread pane */
#threadTree >treechildren::-moz-tree-row {
   height: 25px !important;
}

Thunderbird versions > 115.* have changed the styling, this works for me:

/* Do not remove the @namespace line -- it's required for correct functioning */
/* set default namespace to XUL */
@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
@namespace html url("http://www.w3.org/1999/xhtml");
/* Set Font Size And Spacing In Folder Pane */
html|ul#folderTree html|li[is="folder-tree-row"] > html|div.container > html|span.name {
    font-size: 1.45rem !important;
    line-height: 1.6 !important;
}
/* Set Font Size And Spacing In Thread Pane */
html|table[is="tree-view-table"] {
    font-size: 1.45rem !important;
    line-height: 1.65 !important;
}

This is a proper stylesheet but the crucial point is to switch on toolkit.legacyUserProfileCustomizations.stylesheets as @Nicolai wrote in his answer: https://superuser.com/a/1678560/534153 — heavelock, Feb 17 '22 at 09:24

score 2 · Answer 2 · answered Sep 27 '21 at 21:48

qingu has most of the correct answer, i.e. you need to create a ~/Library/Thunderbird/Profiles//chrome/userChrome.css file containing

/* Set default namespace to XUL */ @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
/* Set font size in folder pane */
#folderTree >treechildren::-moz-tree-cell-text {
    font-size: 10pt !important; }
/* Set font size in thread pane */
#threadTree >treechildren::-moz-tree-cell-text {
    font-size: 10pt !important; }
/* Set height for cells in folder pane /
#folderTree >treechildren::-moz-tree-row {
    height: 20px !important; } / Set height for cells in thread pane */
#threadTree >treechildren::-moz-tree-row {
    height: 20px !important; }

You also must go to the Thunderbird Preferences->Config Editor (last option in the preferences), search for the value toolkit.legacyUserProfileCustomizations.stylesheets and toggle it to True. Without this, the CSS customisation will not be read.

The default size seems to be about 6pt, so 10pt makes it significantly more readable (on a Retina display). The example above also adjusts the height of each row in the message list to match a 10pt font size.

score 2 · Answer 3 · edited Jan 04 '20 at 00:06

2

You need to edit your userChrome.css file.

Go to ~/Library/Thunderbird/Profiles/[yourProfileName]/chrome/ (creating the chrome directory if it doesn't exist) and edit userChrome.css, again creating if it doesn't exist.

For example, to edit all text in Thunderbird (except message view), enter the following:

/* Global UI font */
*
{
    font-size: 18pt !important;
    font-family: Verdana !important;
}

The result looks something like this:

Alt text

Unfortunately, I was unable to find the CSS class for the message list. Replace the * in the CSS content with that CSS class, and it should work as intended.

edited Jan 04 '20 at 00:06

Peter Mortensen

12,190

answered Dec 31 '10 at 11:12

Daniel Beck

110,419

Yes, this example is exaggerated, but how else can I prove it works? – Daniel Beck Jan 26 '11 at 18:30
This solution only helps a little bit, because you only increase the font - but you need to add space for that larger font as well. – May 31 '12 at 13:43
Alternatively, let Thunderbird open the profile folder. In some versions, menu Help → Troubleshooting Information → Open Directory (near "Profile Directory"). – Peter Mortensen Jan 04 '20 at 00:14

score 1 · Answer 4 · edited Mar 18 '16 at 21:35

1

You have to make a folder named chrome in the profile folder. On a Mac it is located in /users/NAMEOFTHEUSER/Libraries/Thunderbird/Profiles/NAMEOFTHEPROFILE/ and there you need to make a new text file named userChrome.css, as discussed in the previous answers.

listitem, treechildren::-moz-tree-row {
    min-height: 2em !important;
}

edited Mar 18 '16 at 21:35

Scott - Слава Україні

21,717

answered Mar 17 '16 at 14:25

Nikola Kołodziejczyk

11

2

Can you expand your answer to explain where the user is meant to enter this code and what it will do? – Burgi Mar 17 '16 at 15:03
You have to make a folder named "chrome" in the profile folder. On a Mac it is located in /users/NAMEOFTHEUSER/Libraries/Thunderbird/Profiles/NAMEOFTHEPROFILE/ and there You need to make a new text file named userChrome.css. Just like the previous answers told – Nikola Kołodziejczyk Mar 18 '16 at 17:59
I suggest you have a read of How to write a good answer. It will explain how SuperUser works and hopefully in future prevent you from having answers deleted or from receiving downvotes. – Burgi Mar 18 '16 at 21:27
Alternatively, let Thunderbird open the profile folder. In some versions, menu Help → Troubleshooting Information → Open Directory (near "Profile Directory"). – Peter Mortensen Jan 04 '20 at 00:15

score 0 · Answer 5 · answered Jun 03 '22 at 09:35

0

The easiest solution I have found is described in this thread: https://support.mozilla.org/en-US/questions/1297871 Might not be perfect but it works at least for me

answered Jun 03 '22 at 09:35

Rosanna

1

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center. – Community Jun 03 '22 at 09:36
While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. - From Review – DarkDiamond Jun 03 '22 at 10:12

Peti · Answer 6 · 2015-09-04T12:15:58.470

0

I use the "Theme Font & Size Changer" add-on: https://addons.mozilla.org/de/thunderbird/addon/theme-font-size-changer/

This add-on gives you a little GUI, where you can easily change the font-size of the thread-list (and the tree), without fiddling around in the css file.

edited Sep 04 '15 at 12:15

answered Sep 04 '15 at 11:35

Peti

101

Please read How do I recommend software for some tips as to how you should go about recommending software. At the very least you should provide more than just/at least a link, for example some additional information about the software itself, and how it can be used to solve the problem in the question. – DavidPostill Sep 04 '15 at 11:57

How can I change the font size of a Thunderbird thread list on a Mac?

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