Fonts are small until a design tool installs four thousand of them
A font is kilobytes and a font library is gigabytes. Where fonts live, which folders are yours to manage, and what removing the wrong one breaks.
Individual fonts are tiny, which is why nobody thinks about them, and font libraries are not, which is why designers occasionally find several gigabytes of them. The other reason to look is speed: applications enumerate every available font at launch, and a very large library is felt rather than only stored.
The four places fonts live
du -sh ~/Library/Fonts /Library/Fonts /System/Library/Fonts \
~/Library/Application\ Support/Adobe/CoreSync 2>/dev/null | sort -h| Location | Whose | Safe to change |
|---|---|---|
~/Library/Fonts | Yours | Yes |
/Library/Fonts | All users on this Mac | Yes, with care |
/System/Library/Fonts | macOS | No. System interface depends on these |
| A sync service's folder | Adobe or another provider | Through that service, not by hand |
Disabling rather than deleting
Font Book can disable a font or a collection, which removes it from every application's font menu while leaving the file in place. For managing a large library that is almost always the right move: the space is a smaller problem than the clutter, and disabling is reversible in a click.
Font Book also has a validation tool that finds duplicates and damaged fonts, which is worth running on a library that has been carried between Macs for years. Duplicate fonts are a real source of odd rendering as well as of space.
Sync services install more than you notice
Design subscriptions can activate hundreds or thousands of fonts, and those are stored locally by the sync client. Deactivating them in the service removes the local files properly; deleting them by hand leaves the service believing they are still installed and it reinstalls them.
What removing a system font breaks
macOS uses specific fonts for its own interface, and removing one from /System/Library/Fonts produces a Mac with unreadable menus. That folder is protected on recent macOS, which is a good thing. Do not attempt to work around the protection to save a few megabytes.
In practice fonts are rarely the answer to a full disk, and this page exists mostly so you can rule them out quickly. If they are not the problem, the disk is full and there is nothing to delete covers where to look next.
Common questions
Where are fonts stored on a Mac?
In ~/Library/Fonts for your account, /Library/Fonts for all users, and /System/Library/Fonts for macOS itself. Sync services such as design subscriptions keep their own folder as well, and those should be managed through the service.
Is it safe to delete fonts on a Mac?
Your own and shared fonts, yes. System fonts, no, since macOS uses them for its interface and removing one can leave menus unreadable. Disabling a font in Font Book is the reversible alternative to deleting it.
Do fonts slow down a Mac?
A very large active font library adds work when applications enumerate available fonts at launch, which is noticeable in design software. Disabling collections you are not using addresses that without deleting anything.
How do I find duplicate fonts?
Font Book's validation tool reports duplicates and damaged fonts. It is worth running on a library carried between machines over years, since duplicates cause inconsistent rendering as well as taking space.