Where apps hide your files

Finding Quick Look plug-ins and extensions

Updated 2026-10-28 · 6 min read

Where Quick Look add-ons live depends on their age: new extensions sit inside the apps that provide them, and the old .qlgenerator plug-ins used Library folders that Sequoia and later ignore. This shows how to find, check and remove both.

The locations

Quick Look add-ons come in two kinds, and they live in different places.

Modern Quick Look extensions (.appex) have no folder of their own. They sit inside the app that provides them:

/Applications/<App>.app/Contents/PlugIns/

Legacy Quick Look generators (.qlgenerator) were installed in one of these places, which Apple's Quick Look Programming Guide lists in the order Quick Look searched them:

<App>.app/Contents/Library/QuickLook/     inside the app that owns the file type
~/Library/QuickLook/                      third-party, just you
/Library/QuickLook/                       third-party, all users
/System/Library/QuickLook/                Apple's own

On the Mac used for this guide (macOS Sequoia 15.6), both ~/Library/QuickLook and /Library/QuickLook exist and are empty. Before you put anything in them, read the next section: on Sequoia and later, third-party generators are ignored wherever they are.

Which kind still works

Apple replaced .qlgenerator plug-ins with app extensions years ago, and Sequoia stopped loading the old kind. Howard Oakley's analysis at Eclectic Light says it plainly: from Sequoia, Quick Look Generator plug-ins no longer work, and previews and thumbnails must come from app extensions. Apple has not published a user-facing page that says so, but the Mac used for this guide agrees: an installed app there still ships only a .qlgenerator inside its bundle, and Quick Look's list of generators ignores it.

In practice:

• On Sonoma 14 and earlier, a .qlgenerator in one of the folders above still works, and so do extensions inside apps.
• On Sequoia 15 and later, a third-party .qlgenerator does nothing. Only extensions inside apps add previews or thumbnails.
• Apple's own .qlgenerator bundles in /System/Library/QuickLook are still there on Sequoia: 20 of them on the Mac used for this guide, such as PDF.qlgenerator, Text.qlgenerator and iWork.qlgenerator. That folder is on the sealed system volume, so you cannot add to it or change it.

Finding the extensions that are installed

Extension names vary: they often contain QuickLook, Preview or Thumbnail, but not always. To see which preview extensions the system has registered, with the app that carries each:

pluginkit -mAvv -p com.apple.quicklook.preview

Each result shows a Path (the .appex) and, for extensions inside an app, a Parent Bundle (the app). On the Mac used for this guide that includes Notes, Shortcuts, Reminders and Safari.

For thumbnail extensions, -p com.apple.quicklook.thumbnail returned "(no matches)" on Sequoia 15.6 even though nine were registered, so filter the full list instead:

pluginkit -mAvv | grep -B3 "SDK = com.apple.quicklook.thumbnail" | grep "Path ="

Both commands only read the registry. To see which legacy generators Quick Look is still using:

qlmanage -m plugins

It lists file types (as identifiers such as com.adobe.pdf) and the generator that handles each. On the Sequoia Mac used for this guide every entry points into /System/Library/QuickLook.

To look inside a single app, Control-click it in Finder, choose Show Package Contents and open Contents: old generators are in Library/QuickLook, extensions in PlugIns.

Turning an extension off or on

Extensions are managed in System Settings, not in a folder.

• Sequoia and later: System Settings > General > Login Items & Extensions. Scroll to the extensions list, click the info button next to Quick Look, switch an extension off or on, then click Done (steps from Apple's Mac User Guide).
• Sonoma: System Settings > Privacy & Security, then Extensions on the right, where Apple's Sonoma guide lists a Quick Look section.

If you cannot see it, type "extensions" into the search field in System Settings.

Installing and removing

• Modern extensions: install the app, usually by dragging it to /Applications, and open it once so macOS registers the extension. To remove it, move the app to the Trash; the extension goes with it.
• Legacy generators (Sonoma and earlier only): drag the bundle into ~/Library/QuickLook (just you) or /Library/QuickLook (all users), then reload Quick Look. To remove one, move it to the Trash and reload again.

The reload command is:

qlmanage -r

It makes Quick Look reload its list of generators and does not touch your files. qlmanage -r cache resets the thumbnail cache, which is also safe: thumbnails are redrawn as you browse. Afterwards, select a file and press Space to test.

Previews are blank or out of date

Check in this order:

1. Confirm the extension is registered with the pluginkit command above, and that its app is in /Applications rather than running from a disk image.
2. Check that it is switched on in the settings described above.
3. Run qlmanage -r and try again. If Finder still shows a generic icon, relaunch Finder: hold ⌥, Control-click the Finder icon in the Dock and choose Relaunch.
4. On Sequoia or later, if all you have is a .qlgenerator, look for an updated version of the app that includes an extension. Moving the generator to another folder will not help.

Moving to a new Mac

Extensions come with their apps, so reinstalling the apps is enough. Only legacy generators in ~/Library/QuickLook need copying, and only if the new Mac runs Sonoma or earlier.

Why a search for qlgenerator finds nothing

Spotlight and Finder searches leave out ~/Library, /Library, /System and the insides of app packages, so a Finder search for qlgenerator or appex comes back empty even when dozens exist. Use Go > Go to Folder (⇧⌘G) with one of the paths above instead.

Finding them next time

Everywhere matches file names inside app packages and system folders, so typing qlgenerator lists every legacy generator on the Mac, including ones hidden in app bundles that no longer do anything, and typing QuickLook finds most of the bundled extensions, since many carry it in their names. ⌘↵ reveals a result in Finder. It cannot tell you whether a plug-in still works on your macOS version; the commands and the settings switch above answer that.

Common questions

Where do I put a qlgenerator file on a Mac?

In ~/Library/QuickLook for one user or /Library/QuickLook for everyone, then run qlmanage -r. This only works on macOS 14 Sonoma and earlier; Sequoia 15 and later ignore third-party .qlgenerator plug-ins.

Why did my Quick Look plug-in stop working after updating to Sequoia?

Sequoia stopped loading legacy Quick Look generator plug-ins. Only Quick Look app extensions (an .appex inside an app) work now, so you need a version of the app that includes one.

How do I see which Quick Look extensions are installed?

Run pluginkit -mAvv -p com.apple.quicklook.preview in Terminal, or open System Settings > General > Login Items & Extensions and click the info button next to Quick Look. On Sonoma, look in Privacy & Security > Extensions.

How do I reset Quick Look on a Mac?

Run qlmanage -r to reload Quick Look's list of generators, and qlmanage -r cache to reset the thumbnail cache. Neither deletes your files.