1. Why Final Cut & Premiere Libraries Balloon to 100+ GB
If you edit video on a Mac with a 256 GB or 512 GB internal SSD, you know the terror of the macOS prompt: "Your disk is almost full."
When you check your Mac storage, you find that your .fcpbundle file (Final Cut Pro Library) or your Adobe scratch disk has silently grown from 5 GB to 120 GB or more.
This is caused by background rendering. Every time you apply color grading, add a title generator, cut a transition, or slow down a clip with Optical Flow, Final Cut Pro and Adobe Premiere automatically render uncompressed ProRes 422 proxy clips in the background to give you real-time timeline playback.
2. The Golden Rule: Render Files vs. Original Media
3. How to Clean Final Cut Pro Render Files
Apple built a native tool inside Final Cut Pro to reclaim this space:
- Open Final Cut Pro.
- In the sidebar, click on your Library (the four-star icon at the top of the browser).
- Go to the top macOS menu bar and click File $\to$ Delete Generated Library Files...
- In the popup modal:
- Check Delete Render Files.
- Select All (or Unused Only if you are actively editing mid-timeline).
- (Optional) Check Delete Optimized Media and Delete Proxy Media if your edits are finished.
- Click OK.
Watch your library shrink instantly from 100+ GB back down to a few hundred megabytes!
4. How to Clear Adobe Premiere Media Cache
Adobe Premiere Pro creates .pek peak waveform files and .cfa conforming audio files in a global directory on your boot drive. Over several projects, this directory easily reaches 40 to 80 GB.
Method A: Inside Premiere Pro Preferences
- Open Premiere Pro and go to Premiere Pro $\to$ Settings (or Preferences) $\to$ Media Cache.
- Next to Remove Media Cache Files, click Delete.
- Choose Delete unused media cache files (or close all open projects to select Delete all media cache files).
Method B: Safe Terminal Purge
If Premiere won’t open or you want to reclaim space immediately without launching Adobe Creative Cloud:
rm -rf ~/Library/Application\ Support/Adobe/Common/Media\ Cache\ Files/*
# Clear peak waveform indices
rm -rf ~/Library/Application\ Support/Adobe/Common/Media\ Cache/*
5. DaVinci Resolve CacheClip Purge
DaVinci Resolve saves rendered timeline clips to its CacheClip folder. If you work in 4K ProRes or Blackmagic RAW, a single 15-minute timeline can produce 50 GB of cached clips.
rm -rf ~/Library/Application\ Support/Blackmagic\ Design/DaVinci\ Resolve/CacheClip/*
Keep Your Mac SSD Free Without Guesswork
CacheMelt is a 3.1 MB native Mac app built with Swift. It scans video caches, audio plugins, Xcode, npm, and system temporary files, reclaiming 50+ GB in 1 click.
- Non-Destructive: Only purges disposable caches, never your original footage or timelines.
- Free Tier Included: Clean up to 3 GB 100% free with no email or signup.
- Zero Bloat: Pure native SwiftUI, Apple Notarized.
6. The 1-Click Way (CacheMelt)
Instead of manually opening every video editing suite, digging into application packages, or searching ~/Library/Application Support, CacheMelt brings all creative and developer caches into a single native dashboard.
You see the exact size of every category on your Mac, pick what to purge, and recover gigabytes in seconds.
7. Frequently Asked Questions
Will deleting render files affect my exported video quality?
No. When you export your final video (e.g. to YouTube, Vimeo, or ProRes Master), Final Cut Pro and Premiere automatically render frames directly from your camera original files at maximum fidelity.
Why did my Final Cut Pro library fill up again after 1 day?
Final Cut Pro has Background Render turned on by default (Preferences $\to$ Playback $\to$ Background render). If you leave this checked, FCP renders every edit automatically after 0.3 seconds of idle time. Unchecking it will prevent unexpected storage consumption!