How to Clear the Font Cache on a Mac When Fonts Render Wrong

In short: When menus turn to boxes, a typeface suddenly looks wrong, or the same font renders differently across apps, a corrupted font cache is often the cause. Here is how to clear and rebuild it on macOS Sonoma and Sequoia without breaking anything.

Fonts are one of the quieter parts of macOS, so when they go wrong it feels alarming. You might see a paragraph render in the wrong typeface, letters replaced by empty boxes or question marks, text that looks unexpectedly bold or spaced strangely, or the same font that looks fine in one app and broken in another. Before you start reinstalling fonts one by one, it is worth knowing that macOS keeps a font cache to speed up rendering, and when that cache gets stale or corrupted it can produce exactly these symptoms.

This guide walks through how to clear the font cache on a Mac and rebuild it cleanly on macOS Sonoma (14) and Sequoia (15). None of the steps below delete your actual fonts, and every step is reversible.

What the font cache actually is

To avoid re-parsing every font file on every launch, macOS stores a compiled cache of your installed fonts. The system maintains this automatically. The cache is not your fonts themselves, it is a derived index built from them, so clearing it is safe: macOS simply regenerates it the next time it needs to draw text. Think of it like emptying a scratchpad, not shredding the original document.

Because the cache is disposable by design, the right fix for rendering glitches is almost always to remove the cache and let the system rebuild it, rather than touching font files in Font Book.

First, rule out the simple stuff

A cache reset is a real fix, but a lot of "font" problems have simpler causes. Spend two minutes here first:

• Restart the app. Quit the misbehaving app completely (Cmd-Q, not just closing the window) and reopen it. Many rendering glitches live only in a single running process.
• Check Font Book for conflicts. Open Font Book, then choose Edit > Look for Enabled Duplicates. Duplicate or conflicting copies of the same font are a very common cause of the wrong weight or style showing up. Let Font Book resolve them.
• Validate the font. In Font Book, select the suspect font and choose File > Validate Font. A font flagged with warnings or errors may be the real culprit, and no cache reset will fix a broken font file.
• Reboot once. A plain restart clears a lot of transient state and sometimes fixes rendering on its own.

If fonts still render wrong after that, move on to clearing the cache.

How to clear and rebuild the font cache

The supported, low-risk way to reset the font cache uses a single Terminal command plus a restart. Open Terminal (in Applications > Utilities), then run:

sudo atsutil databases -remove

You will be prompted for your administrator password (the cursor will not move as you type, which is normal). This command tells the Apple Type Services utility to remove its font cache databases. You can optionally follow it with atsutil server -shutdown and atsutil server -ping to restart the font server, but the cleanest approach is simply to restart your Mac afterward. On the next boot, macOS rebuilds the cache automatically from your installed fonts.

That is the whole procedure. There is no menu item that does this for you, and there is no need to hunt through hidden system folders or delete files inside /System (don't do that, it is protected for good reason). The atsutil command is the tool Apple provides for exactly this job.

If problems persist after rebuilding

If text still renders incorrectly after clearing the cache and restarting, the problem is likely a specific font file rather than the cache. Try these, in order:

1. Return to Font Book and disable the suspect font (right-click, then Disable). Disabling is fully reversible, so you can turn it back on anytime.
2. If a third-party or recently installed font caused it, remove that font from Font Book and, if you have the original file, reinstall a fresh copy.
3. Restart once more so the rebuilt cache reflects the change.

Because you have only disabled or removed the fonts you added yourself, your system fonts stay untouched and everything you do here can be undone.

A quick word on safety and reversibility

When you clean anything on a Mac, keep two habits: only touch user-level caches by default, and make sure removals go to the Trash rather than being permanently deleted. Trash is your undo button. If clearing a cache turns out to be the wrong move, you can put the files back. This is why it is smart to avoid tools or commands that permanently erase data, and to leave system-protected locations alone.

The same logic applies to any cleaning utility you install: it should preview what it plans to remove before it acts, default to user-level junk only, and send everything to the Trash so nothing is irreversible. A cleaner also has no legitimate reason to phone home, and you can confirm that yourself with a firewall like Little Snitch and watch whether it makes outbound connections.

If you would rather not run Terminal commands by hand for routine cache cleanup, a well-behaved app can handle the preview-and-Trash workflow for you. For a free option that fits those principles, CoreSweep is a solid pick (free forever, an optional one-time Pro at $49, zero telemetry, and every removal goes to the Trash so it is reversible). If you want the best value, SkoonMac is a strong runner-up, free to use with a one-time $19 Pro. Either way, the goal is the same: fix the rendering, keep your fonts, and never delete anything you can't get back.

Frequently asked questions

Does clearing the font cache delete my fonts?

No. The font cache is a derived index macOS builds from your fonts to speed up rendering, not the fonts themselves. Clearing it is safe because the system simply regenerates it the next time it needs to draw text. Your actual font files stay untouched.

How do I clear the font cache on macOS Sonoma or Sequoia?

Open Terminal (in Applications > Utilities) and run: sudo atsutil databases -remove, then enter your administrator password. Restart your Mac afterward so macOS rebuilds the cache automatically from your installed fonts on the next boot. That atsutil command is the tool Apple provides for this, so there is no need to hunt through hidden system folders or delete files inside /System.

Why are my fonts rendering wrong, showing boxes or the wrong weight?

A stale or corrupted font cache is a common cause of boxes, question marks, wrong typefaces, or a font that looks fine in one app but broken in another. Before clearing the cache, rule out simpler causes first: quit and reopen the app, check Font Book for enabled duplicates, and validate the suspect font. If text still renders wrong after that, clearing and rebuilding the cache is the right next step.

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