Help · Mac storage

Final Cut Pro library too big?

By Grant and Brad, who make Pangalin's apps · Updated 11 October 2026

A Final Cut Pro library can grow many times bigger than the footage you imported. Usually that's not your media: it's files Final Cut generates to make editing smooth, and you can delete or relocate them.

What makes a library grow

• Render files: previews of effects, titles and colour work, created as you edit (and in the background, if background rendering is on).
• Optimised and proxy media: extra copies of your footage in easier-to-edit formats, if you chose to create them.
• Imported media copied into the library: if you import with Copy to library, the footage itself lives inside it.

Shrink it safely

1. Delete generated files. Select the library (or an event or project), then choose File › Delete Generated Library Files… and pick render files and, if you don't need them, optimised and proxy media. Final Cut can recreate them later.
2. Put caches and renders elsewhere. Select the library, open the Inspector, and under Storage Locations click Modify Settings to point the cache at an external drive.
3. Consider turning off background rendering in Final Cut Pro › Settings › Playback. Final Cut then renders only when you ask.
4. Leave media in place on future imports (choose Leave files in place) if you'd rather keep footage on an external drive.

Close Final Cut Pro before moving a library in Finder, and keep a backup of any library you care about before big clean-ups.