How to Clear Quick Look's Cache on Mac

Quick Look is one of the most-used Mac features that nobody calls by name. Press space on any file, get an instant preview. Most of the time it just works. When it doesn’t, you get stuck previews showing old versions of files, broken thumbnails, or Quick Look refusing to preview supported file types.

The fix is usually a Quick Look cache clear. Here’s the actual layout on macOS Sonoma 14 and Sequoia 15.

Where Quick Look caches data

Quick Look maintains caches in several places:

• ~/Library/Caches/com.apple.QuickLookDaemon/ — preview cache
• ~/Library/Caches/com.apple.quicklook.satellite/ — extended cache
• /private/var/folders/.../C/com.apple.QuickLook.thumbnailcache/ — thumbnail cache (random folder hash)

The path with random hashes makes it hard to find directly. The standard tools handle this for you.

There’s also ~/Library/Caches/com.apple.QuickLookThumbnailing.ThumbnailsAgent.thumbnails-history.db which tracks the thumbnail history.

The supported way: qlmanage

Apple ships qlmanage, a Terminal command for managing Quick Look. To reset its cache:

qlmanage -r cache

That command rebuilds the Quick Look cache. No restart required. The command runs and returns to your prompt; Quick Look will rebuild caches as you preview files going forward.

You can also reset the Quick Look generators:

qlmanage -r

This restarts the Quick Look daemon and reloads installed Quick Look plugins. Useful if you’ve installed a Quick Look plugin (like QLMarkdown or Suspicious Package) and it’s not registering.

The brute-force approach

If qlmanage isn’t doing it:

1. Quit any apps using Quick Look extensively (Finder doesn’t count — Finder will be fine).
2. Open Finder, press Cmd+Shift+G.
3. Paste ~/Library/Caches/com.apple.QuickLookDaemon/.
4. Move contents to Trash.
5. Repeat for ~/Library/Caches/com.apple.quicklook.satellite/.
6. Empty Trash.
7. Run qlmanage -r in Terminal to restart the Quick Look daemon.

Quick Look rebuilds caches as you preview files.

Clearing the system thumbnail cache

The thumbnail cache lives in a folder with a random hash, but you can find it via Terminal:

sudo find /private/var/folders -name "com.apple.QuickLook.thumbnailcache" -type d

This locates the actual path. Then to clear:

sudo rm -rf /private/var/folders/[hash]/[hash]/C/com.apple.QuickLook.thumbnailcache

Replace the bracketed parts with the actual hash from the find command.

Easier alternative: just restart your Mac. The thumbnail cache rebuilds from scratch on boot.

Don’t dig through ~/Library yourselfSweep knows where every app stores its cache. Free download for Mac →

When Quick Look problems happen

Common triggers for Quick Look misbehaving:

• Installing or updating Quick Look plugins (third-party preview generators)
• macOS major version upgrades
• Replacing files outside Finder (rsync, command-line operations)
• Network drives showing old previews of files that have changed
• Working with very large files that exceeded Quick Look’s preview limits

What it looks like:

• Pressing space shows old version of a file you just modified
• Thumbnails in Finder showing wrong content
• Quick Look refusing to preview file types it normally handles
• Spinning loader instead of preview
• Text files showing as just file icons with no preview

Quick Look plugins

Third-party Quick Look plugins live at:

• /Library/QuickLook/ — system-wide plugins
• ~/Library/QuickLook/ — user plugins
• Inside app bundles for apps that ship Quick Look extensions

Common useful ones:

• QLMarkdown — preview markdown files
• Suspicious Package — preview .pkg installer contents
• QLVideo — preview obscure video formats
• WebPQuickLook — preview WebP images
• QLColorCode — syntax-highlighted code preview

If a plugin is misbehaving, removing it from ~/Library/QuickLook/ and running qlmanage -r clears it from Quick Look’s plugin registry.

Modern Quick Look extensions

In addition to the legacy plugins above, modern Quick Look uses app extensions managed via System Settings → Privacy & Security → Extensions → Quick Look.

You can enable or disable Quick Look extensions per app there without uninstalling anything. Useful when an extension is causing trouble.

There’s a faster waySweep finds and clears caches across every app you use, all at once. Try Sweep free →

Resetting Finder along with Quick Look

If Finder thumbnails look wrong (separately from Quick Look previews), restarting Finder helps:

killall Finder

Finder relaunches automatically. Combine with qlmanage -r for a full reset.

What about iconservicesagent?

Related to Quick Look: the icon cache. Sometimes Quick Look problems are actually icon problems. To reset that:

sudo killall iconservicesagent

Or reset more aggressively:

sudo rm -rf /Library/Caches/com.apple.iconservices.store
sudo killall iconservicesagent

Restart Finder (killall Finder) afterward.

How much space does Quick Look cache take?

Not much. User-level Quick Look caches usually total under 500MB. System thumbnail cache can hit 1-2GB on Macs with lots of unique files, but typically less.

This isn’t really a space-saving exercise — it’s a “fix Quick Look when it’s broken” exercise.

How often to clear

Never proactively. The cache doesn’t grow unboundedly to a problematic size.

Clear it when:

• Previews are showing old versions of files
• Thumbnails are visibly wrong
• Quick Look refuses to preview supported file types
• After installing or updating a Quick Look plugin

When clearing Quick Look won’t help

Cache clears don’t fix:

• Files that are genuinely corrupt (Quick Look can’t preview broken files)
• Files in formats Quick Look doesn’t support (you need a plugin or different app)
• Network drive issues (slow connection, not cache)
• App-specific preview features (Pages preview vs. Pages Quick Look extension are different things)

Quick Look on external drives

Quick Look works the same on external drives. The cache is still kept locally on your Mac, not on the external drive. If you preview files on an external drive then disconnect it, the thumbnails might show in Finder briefly (cached) but won’t fully preview without the drive connected.

A broader cache picture

Quick Look is one of dozens of system caches macOS maintains. Others include:

• App caches (per-app, in ~/Library/Caches/)
• Browser caches
• Spotlight index
• Mail database and downloads
• Photos derivatives
• Music streaming cache
• iCloud sync caches

Each has its own clearing approach. For Quick Look specifically, qlmanage is the right tool. For broader Mac maintenance, Sweep handles app caches, system caches, and other accumulated junk in one scan, showing what’s reclaimable before deleting anything. Free download for macOS Sonoma 14 and Sequoia 15.

Bottom line

Quick Look’s cache lives at ~/Library/Caches/com.apple.QuickLookDaemon/ and related folders. The supported clearing command is qlmanage -r cache. Manual deletion plus qlmanage -r works as a fallback.

Quick Look cache problems are obvious when they happen — wrong previews, broken thumbnails. If everything’s working, leave it alone.