How to reset fonts in macOS Tahoe using Font Book

If you’ve added third party fonts to apps such as Pages in macOS and the apps are running slow, you may need to reset the fonts. 

Resetting fonts in Font Book on macOS “Tahoe” moves all non-standard, user-installed fonts to a new folder, making them unavailable to apps, and restores the system’s default fonts. This is a way to troubleshoot font-related issues by returning to a clean state, with the user-installed fonts saved in a separate location for later reinstallation if needed. 

When you reset fonts, non-standard fonts are removed. Any fonts you have installed that were not part of the original macOS installation are moved to a folder named Fonts (Removed). The moved fonts are no longer available for use in applications because they have been deactivated. 
What’s more, system fonts are restored. The action restores the original, pre-installed fonts that came with macOS. Conveniently, this process doesn’t delete your custom fonts permanently; it only moves them to a separate, inactive folder. 

To perform a font system reset:

1. Open the Font Book application.
2. Go to Font Book > Settings.
3. Click on Advanced.
4. Click the Reset Fonts button.
5. Confirm by clicking Proceed and enter your password or use Touch ID if prompted. 
   

To re-enable your custom fonts

• You can find your moved fonts in the /Library/Fonts (Removed) or /~/Library/Fonts (Removed) folders.
• If you wish to use them again, you can reinstall them one by one.