If a font doesn’t display correctly in a document, the font file may be damaged. If a document won’t open, it’s possible one of the fonts used in the document is the problem. Using Font Book, you can test fonts for problems and remove them. You can also validate fonts before you install them to head off future problems. Validating fonts at installation cannot prevent the files from becoming damaged later, but it prevents you from installing problem files. Font Book is included with macOS Big Sur (11) through OS X 10.3. You can find Font Book in the Applications folder. You can also launch Font Book by selecting the Go menu in the Finder menu bar, choosing Applications, and then double-clicking the Font Book application.
How to Validate Installed Fonts With Font Book
If you have a problem with a font, check it in Font Book. You can also verify all fonts on your Mac occasionally to err on the side of caution. Here’s how to validate installed fonts in Font Book: You are prompted by your Mac to enter your password before it removes the damaged font. If you see a problem font indicated by a red circle with an X in it, select the check box next to the font name and select Remove Checked to delete it. If you have a large number of fonts installed, you can validate them all at once, rather than selecting individual fonts or font families. Select Edit on the Font Book menu bar and choose Select All. In the File menu, select Validate Fonts, and Font Book validates all the installed fonts.
Remove Duplicate Fonts
If you validate all your fonts, you may find duplicate fonts. A banner at the bottom of the Font Book screen notifies you if you have duplicates. Choose Resolve Automatically to remove duplicates all at once without a review. A more cautious approach is to select Remove Manually to find out more about the duplicate fonts on your Mac. Each font with a duplicate is displayed, one at a time. You are shown samples of both fonts, and the active copy is identified. You can choose to resolve the duplicate, which moves the inactive copy to the trash, or you can leave everything as is.
How to Validate Uninstalled Fonts With Font Book
If you have collections of fonts on your Mac that you have not installed, you can wait until you install them to validate them, or you can check them in advance and toss any fonts that Font Book labels as possible problems. Font Book is not foolproof, but chances are if it says a font is safe to use (or that it has problems), the information is correct. It’s better to pass on a font than risk problems down the road. To validate a font file before installing it:
