Final Cut Pro, Logic and Adobe caches: reclaim space from creative apps

Part of: Mac disk cleanup for developers: every cache, what it costs to rebuild (Developers)

Final Cut Pro, Logic Pro and Adobe apps all generate large files next to your projects: render files, preview files, media caches and sound packs. Most can be recreated by the app, but your originals and finished projects are not part of that. Clear the generated files from inside each app, not by deleting folders by hand.

This is a short bridge for people who edit video or music as well as code. We have not used each app on the Mac used to check this article, so this guide stays with general principles and tells you where to look for numbers. It avoids exact menu paths, since they change between versions.

Generated files and originals

The key distinction is between two kinds of files:

• Originals: your imported video, audio, photos and the project itself. These are not cache and are not recreated.
• Generated files: renders (video the app computes so playback is smooth), proxy and optimized media (lighter copies made for editing), waveforms, thumbnails and media caches. The app can rebuild these from the originals.

Only the second kind is a candidate for cleanup. If you are not sure which kind a file is, leave it.

Safe, risky, never

• Safe: render files, optimized media, proxy media, media caches and waveform caches for projects you are not working on. Cost: re-rendering or re-generating them, which can take a while for long projects.
• Risky: generated files for a project with a deadline, and sound packs or loops that you actually use. Cost: re-download of a large pack, or waiting for a long render.
• Never: do not open a Final Cut library package and delete files inside it, and do not remove original media or an exported master. Do not delete files in an Adobe cache folder while an app is open.

Final Cut Pro

Final Cut keeps your project data in a library, which appears in Finder as a single file but is really a folder. Generated files can live inside the library or in a folder you chose. The app has its own command for deleting generated library files, such as render files, optimized media and proxy media. Use that, and choose which kinds to remove.

The cost is that Final Cut makes them again when you need them, and it plays back with less smoothness until it does. Original media is not touched by that command.

Logic Pro

Logic’s large items are sound content: instruments, loops and sample libraries. These are downloaded, and the app lets you download and remove packs. If a pack is large and you never use it, remove it from inside Logic. The cost is a re-download when you want it back.

Logic also keeps bounce and audio files in your project folders. Those are your work. Do not remove them to save space unless you have a copy.

Adobe apps

Adobe video apps keep a media cache, a set of files for quick previews and waveforms, and a database that tracks them. The apps have a setting for cleaning the cache. Use it, with your projects closed, so the database stays consistent. The cost is that the next time you open a project, the app regenerates previews, which takes time.

Photoshop and other Adobe apps also use scratch files while open, and they clean up when the app closes properly. A scratch file that stays behind after a crash is safe to remove when the app is not running, but check the size and the app’s own documentation before you do.

How to check how much space they use

Use Finder’s Get Info on a library or project folder, or Terminal:

du -sh ~/Movies/* ~/Music/*

This lists the sizes of items in your Movies and Music folders, where many creative projects live. Your cache and library locations can be different if you chose another disk or folder. Use the app’s own storage settings to learn where its files are.

For general Library caches, see what is safe to delete in Library/Caches, and for leftover data from apps you removed, see app leftovers. Big media files are also frequently duplicated, so finding duplicate files can help. The developer map is in the developer cleanup guide.

Worked example: sizing your media folders

Say your disk is nearly full and you edit video. Start with a read-only look at the big folders:

du -sh ~/Movies

On the Mac used to check this article, the Movies folder was about a hundred megabytes, since it was not used for editing. On a Mac where you edit, it may be hundreds of gigabytes. The number tells you whether media is even the problem.

If it is large, use Finder’s Get Info on each library or project. That shows the size of each one. Pick the oldest finished project first. In its app, use the app’s own command to remove generated files, then check the size again.

Back up before you remove

For a finished project, the safest path is: export the master, keep the original media, and then remove generated files. A finished export and the original footage are enough to rebuild the rest. If you are not sure the export is complete, play it from start to end before you remove anything. A missing or broken export is the one thing you cannot make again from a cache.

If something goes wrong

• Playback stutters after removal. The app is making renders again, or has not made them yet. Wait, or render the section again.
• A project shows missing media. The originals were moved or were on a disk that is not connected. Reconnect the disk. This has nothing to do with the cache.
• The library is still large. Generated files may be stored in a different folder, such as one on an external disk. Check the project’s storage settings in the app.
• An Adobe app is slow to open a project. It is rebuilding previews and the cache database. Let it finish.

When not to clean

Do not remove generated files for a project that is due soon. Rendering a long timeline again can take hours. Wait for delivery, then clean up. Keep sound packs you use every week, because they are large to download again.

See sizes in a scan

DiskJoy is our product. Its scan reads your disk and shows how large your library and project folders are, read-only. Cleanup is not built yet, so DiskJoy does not remove generated files today.