If you've been editing video on your Mac for any length of time, you've probably noticed Premiere Pro quietly consuming enormous amounts of disk space. The most common question that comes up: is it safe to delete Premiere Pro media cache files? The short answer is yes — but understanding what you're deleting, and how to do it cleanly, will save you from surprise slowdowns and regeneration headaches on your next edit session.
What Are Premiere Pro Media Cache Files?
Every time Premiere Pro ingests a video or audio clip, it generates a set of companion files designed to speed up playback, waveform display, and timeline scrubbing. These files fall into two broad categories:
- Peak files (.mpk, .pek) — store audio waveform data so Premiere doesn't have to re-scan the audio every time you open a project.
- Conformed audio files (.cfa) — a re-encoded, normalized version of each audio track, written in a format Premiere can read at sample-accurate speed.
- Media cache database files (.mcdb, .idb) — index files that map your source media to its corresponding cache entries. Deleting these requires Premiere to rebuild the entire index.
Premiere also writes render cache — preview files built when you hit Return to render a timeline segment. These live in a separate location and are covered below.
Where Does Premiere Pro Store Cache Files on macOS?
By default, Premiere Pro splits its cache across two locations on macOS. The exact paths depend on whether you've customized the scratch disk settings, but the factory defaults are:
- Media Cache files:
~/Library/Application Support/Adobe/Common/Media Cache Files/ - Media Cache database:
~/Library/Application Support/Adobe/Common/Media Cache/
Many editors redirect these to an external drive or a dedicated fast SSD to keep the system volume clean. You can check (and change) your current setting inside Premiere at Preferences > Media Cache. The dialog shows the exact path in use, which is the only reliable way to confirm the real location on your machine.
Render preview files (the orange/green bar segments above your timeline) live in a project-relative folder called Adobe Premiere Pro Preview Files, placed alongside your project file by default. They are separate from the media cache and are safe to delete independently.
How Much Space Can Media Cache Use?
The honest answer is: a lot. Conformed audio files alone can consume hundreds of megabytes per hour of footage. Add peak files and database indexes, and a moderately active editor on macOS can easily accumulate 20–60 GB over a few months. Heavy workflows — documentary editors, colorists ingesting raw R3D or BRAW dailies — routinely see 100 GB or more.
| Cache Type | Extension | Typical Size per Hour of Footage | Safe to Delete? |
|---|---|---|---|
| Conformed audio | .cfa |
150 – 400 MB | Yes |
| Peak (waveform) files | .mpk, .pek |
5 – 20 MB | Yes |
| Cache database index | .mcdb, .idb |
Small (< 5 MB total) | Yes (forces full rebuild) |
| Render preview files | .mpeg, project-specific |
500 MB – several GB | Yes (timeline re-renders on play) |
What Actually Happens When You Delete the Cache?
Nothing permanent or destructive happens to your source footage or project files. Media cache files are 100% derived data — Premiere regenerates them from your original media whenever it needs them. Here is what you will actually experience after a deletion:
- First open after deletion: Premiere will show a progress bar conforming audio and rebuilding peak files for any clips it encounters. On a large project this can take several minutes.
- Audio waveforms: They will be blank or missing on the timeline until the .pek/.mpk files are rebuilt for each clip.
- Playback performance: May feel sluggish for the first few minutes until the new conformed audio files are written to disk.
- Render previews (if deleted separately): The green/orange render bar above the timeline reverts to red or yellow, and you'll need to re-render those segments before export.
None of this affects your edit decisions, color corrections, audio mixing, or sequence settings. Your .prproj file is entirely unaffected.
How to Delete Premiere Pro Media Cache on Mac (Step by Step)
Adobe recommends using the built-in cleanup dialog rather than deleting files directly in Finder, because the in-app tool also updates the database index correctly.
- Quit all open Premiere Pro projects and close the application completely.
- Reopen Premiere Pro (no project needs to be open — you can use the Home screen).
- Go to Premiere Pro > Preferences > Media Cache (on macOS, Preferences is under the Premiere Pro menu, not Edit).
- Click Delete next to "Delete Media Cache Files." You'll see two options:
- Delete unused media cache files — removes cache for media that is no longer linked to any open project. Safest option.
- Delete all media cache files — wipes everything. Use this when you need maximum reclaimed space.
- Click OK, wait for Premiere to finish, then reopen your projects normally.
If you prefer to do it from the Terminal — for example as part of a cleanup script — you can safely remove the contents of the cache folders while Premiere is fully quit:
rm -rf ~/Library/Application\ Support/Adobe/Common/Media\ Cache\ Files/*rm -rf ~/Library/Application\ Support/Adobe/Common/Media\ Cache/*
Do not delete the parent folders themselves, only their contents, so Premiere can write new files into the same location on next launch.
When Should You Delete vs. Keep the Cache?
Not every situation calls for a full wipe. Here are the practical decision points:
- Project is finished and archived — delete all cache for that project. You won't pay the regeneration cost unless you reopen the project.
- Running low on disk space before a deadline — use "Delete unused" to reclaim space from old projects without touching the active one.
- Cache database is corrupt (Premiere shows repeated "media pending" errors) — delete everything and let Premiere rebuild from scratch.
- Mid-project with active deadlines — avoid deleting. The regeneration time on a large project can interrupt your workflow for 10–20 minutes.
If you want visibility into exactly how much space the cache has accumulated alongside other culprits like other hidden storage consumers on your Mac, a tool like Crumb can audit all of these folders at once and show what's safe to remove before you delete anything.
Other Adobe Cache Folders Worth Knowing About
Premiere Pro is not the only Adobe app writing cache to your Mac. If you're reclaiming space, these related folders are worth checking:
- After Effects Disk Cache:
~/Library/Caches/Adobe/After Effects/<version>/— can reach 100 GB if you haven't set a cap in AE preferences. - Adobe Media Encoder cache: Lives in the same Common Media Cache folder as Premiere by default.
- Lightroom catalog previews:
~/Pictures/Lightroom/<catalog name> Previews.lrdata/— a common surprise at 20–40 GB for photographers who also use Premiere. - Creative Cloud downloaded assets:
~/Library/Application Support/Adobe/CoreSync/— synced fonts and libraries; selectively removable via the CC app.
For a broader look at how cache files work on macOS generally, the mechanics are consistent — caches are always regenerable derived data, never originals.
Tips for Keeping Cache Under Control Long-Term
Rather than doing a large manual cleanup every few months, a few habits will keep Premiere's cache footprint manageable on macOS Sequoia and later:
- Set an automatic deletion schedule — Premiere's Preferences > Media Cache panel includes an option to delete cache files older than a set number of days (30–90 days is reasonable for most workflows).
- Redirect cache to an external drive — keeps your internal SSD clear. An NVMe external drive over Thunderbolt works well even on Apple Silicon machines.
- Archive projects before clearing — use File > Project Manager to consolidate a finished project, then delete its cache without worrying about future regeneration cost.
- Set an After Effects disk cache cap — AE's disk cache is uncapped by default. Set a maximum (e.g., 50 GB) in AE Preferences > Media & Disk Cache to prevent runaway growth.
On a modern Mac with an internal SSD — especially the space-constrained 256 GB or 512 GB configurations common on Apple Silicon MacBook Pros — proactive cache management is not optional. It's the difference between a machine that stays snappy and one that hits Storage Almost Full warnings in the middle of an edit.