The Adobe media cache on a Mac: Premiere and After Effects

The Adobe media cache on a Mac is a set of files that Premiere Pro, After Effects and Media Encoder make from the footage you import: conformed audio, peak files for waveforms and index files, plus a small database that links each one to its source clip. By default they sit in your Library folder, in ~/Library/Application Support/Adobe/Common.

It's safe to clear. Adobe says deleted cache files are recreated whenever the source media needs them, and the catalog rates the folders as Safe: your footage, projects and exports aren't touched. The cost is time, because the next project you open has to rebuild what it needs.

The best way to clear it is from inside the apps. In Premiere, choose Premiere › Settings › Media Cache and click Delete next to Remove Media Cache Files. The same pane can delete old files automatically, by age or by size, and move the cache to another drive.

What the media cache doesn't include matters just as much. Render previews, proxies and auto-saved project versions live with your projects, and they're your work, not a cache. After Effects also keeps a separate disk cache of rendered frames. This post covers all of them, and which ones you can safely let go.

What the media cache is, and why it grows

When you import a clip, the Adobe video apps don't play it straight from the file every time. They process parts of it once into forms they can read quickly, and keep those results so they don't have to do the work again on every preview.

What do Premiere and After Effects put in the media cache?

Adobe names the main file types. Imported audio is conformed to a new .cfa file. Peak files, ending in .pek, hold the waveform you see on audio clips. MPEG files are indexed to a new .mpgindex file. Adobe's automatic cleanup also mentions .ims files alongside the other two.

Next to the files sits the media cache database. Adobe describes it as a folder containing a database that retains links to each of the media cache files. The files live in Media Cache Files, and the database in Media Cache.

File or folder	What it holds	Made again by the app?
.cfa files	Audio conformed to a format the app reads quickly	Yes, when the clip is used
.pek files	Peak data for audio waveforms	Yes
.mpgindex files	An index of MPEG footage	Yes
.ims files	Cache files Adobe's cleanup also removes	Yes
Media Cache folder	The database linking cache files to clips	Yes

Which apps share it?

Premiere, After Effects and Media Encoder share one media cache database. Adobe's After Effects documentation says each app can read from and write to the same set of cached files, and that changing the database's location in one app changes it for the others too.

Each app can still use its own folder for the cache files themselves, with the shared database keeping track of all of them. That's why one folder can hold files from all three apps, and why clearing it in one app affects the others.

Why does it keep growing?

Because nothing removes old files by default. Adobe's own documentation lists Do not delete cache files automatically as the default in Premiere's Media Cache settings. Every clip from every project you've opened adds files, and they stay after the project is finished and archived.

The catalog's rule says the same: the files stay after a project is finished, so the folders grow over time. For someone who edits for a living, years of finished jobs can turn this into one of the larger folders in their Library.

Does clearing it speed up Premiere?

Adobe calls clearing the media cache regularly a best practice for performance and troubleshooting, because damaged or stale cache files can cause playback errors. Clearing them frees disk space and can fix those problems.

It doesn't make your Mac faster in general. Right after a full clear, Premiere is slower to open projects, since it rebuilds the files it needs. The benefit is space back and a fresh cache, not speed.

Where the Adobe media cache is on a Mac

On a Mac where nobody changed the settings, both folders sit in the same place. Adobe's manual-deletion page gives the parent folder, and the catalog rule names the two folders inside it:

• ~/Library/Application Support/Adobe/Common/Media Cache Files, the cache files
• ~/Library/Application Support/Adobe/Common/Media Cache, the database

The tilde stands for your home folder. Both folders belong to your account, so every account on the Mac has its own.

How do you open the folder in Finder?

The Library folder is hidden by default. In Finder, hold down Option and choose Go › Library, then open Application Support, Adobe and Common. Or choose Go › Go to Folder and type the path above.

Select a folder and choose File › Get Info to see its size. It can take a moment to count a large cache.

What if the cache isn't there?

Then someone moved it. In Premiere, open Premiere › Settings › Media Cache; the pane shows the current location of the cache files and the database. Media Encoder's documentation adds that if the path is cut short, clicking Browse shows it in full.

Media Encoder also has a setting called Save Media Cache files next to originals when possible. With it on, some cache files are written beside your footage, on whatever drive the footage is on, rather than in the Common folder.

Which other Adobe folders are caches?

Only these two, as far as the catalog is concerned. Adobe's Application Support folder holds much more, including settings and the files Creative Cloud syncs, and the rule deliberately doesn't match the Common folder itself or other folders such as CoreSync.

The Application Support folder as a whole is rated Review first, because it holds apps' own data. The post on what's in the Application Support folder explains why it's never cleared wholesale.

Folder	What it is	Safe to clear?
Adobe/Common/Media Cache Files	Media cache files	Yes, apps closed
Adobe/Common/Media Cache	The media cache database	Yes, apps closed
Adobe/Common itself	Parent of shared folders	No, clear only the two inside
After Effects disk cache folder	Rendered frames for previews	Yes, with Empty Disk Cache
~/Library/Preferences/Adobe	The apps' settings	No, these aren't caches

Where does Storage settings count it?

Because it lives inside your Library folder rather than in an app or a document folder, Storage settings usually counts it as part of System Data. That's why a busy editor's System Data can look far larger than expected.

The guide to System Data explains why that category gets so large, and the post on what System Data is made of breaks it down part by part.

How to clear the media cache in Premiere

Premiere has three ways to clear its cache: a button in its settings, an option when it starts, and deleting the folders by hand. Adobe documents all three.

Delete unused or all cache files from Settings

1. Open Premiere. To clear everything, choose File › Close All Projects first.
2. Choose Premiere › Settings › Media Cache. In older versions the menu is called Preferences.
3. Click Delete next to Remove Media Cache Files.
4. In the Delete Media Cache Files dialog, choose what to delete, then click OK.

Adobe adds that to remove all media cache files, you should restart Premiere and choose the option before opening any project.

What's the difference between unused and all?

Delete unused media cache files removes files made for source media that can no longer be found: footage you deleted, renamed or left on a drive that's no longer around. It's the gentle option, and it leaves the cache for current projects alone.

Delete all media cache files from the system removes everything in the current location. Adobe says deleted files are recreated automatically whenever source media requires them, so the price is rebuild time when you next open each project.

Be careful with the unused option if your footage lives on external drives. A clip on a drive that isn't connected looks missing, and its cache files count as unused. Connect your media drives first.

Clear the cache as Premiere starts

Adobe documents a reset option at launch, meant for routine maintenance and for troubleshooting before an update:

1. Quit Premiere.
2. Hold down Command while Premiere opens.
3. When the Reset options dialog appears, select Clear media cache files.

This clears the cache before any project loads, which is exactly the state Adobe recommends for a full clear.

Delete the folders by hand

Adobe's steps for deleting the files manually start with quitting the app. With it closed, go to the Common folder and delete the files, then empty the Trash.

1. Quit Premiere, After Effects and Media Encoder.
2. In Finder, open ~/Library/Application Support/Adobe/Common.
3. Move Media Cache Files and Media Cache to the Trash.
4. Empty the Trash when you're sure nothing is missing.

Adobe notes that deleting the files with Premiere closed also removes the current cache files, which is what you want when troubleshooting errors. Until you empty it, the Trash keeps everything, and File › Put Back returns it.

What happens the next time you open a project?

Premiere rebuilds what it needs. Adobe warns that a delay occurs after deleting all cache files and opening a current project, and that for a large project you should budget enough time for the files to rebuild.

Waveforms may take a moment to appear, and audio may need conforming again before it plays smoothly. Nothing in the project itself changes.

Automatic cleanup: limits by age and size

The most useful setting in this pane is one most people never touch. Premiere can delete old cache files by itself, either by age or when the cache grows past a size.

Where are the automatic options?

Open Premiere › Settings › Media Cache and look under Media Cache Management. Adobe lists three options:

• Do not delete cache files automatically: the default.
• Automatically delete cache files older than: a number of days, 90 by default.
• Automatically delete oldest cache files when cache exceeds: a size, by default 10% of the volume the cache is on.

When does the cleanup run?

Not right away. Adobe says changes take effect after you quit and restart Premiere. On the next launch it checks whether files meet the criteria and, if so, starts deleting them 10 minutes after launch. From then on, this housekeeping runs weekly.

Adobe also says automatic deletion applies only to .pek, .cfa and .ims files inside the Peak and Media Cache Files subfolders. The database stays, and so does anything outside those folders.

What does the size limit mean on your Mac?

The default size limit scales with the disk. On a Mac with one internal drive, 10% of the volume is a sizeable amount of space to give to a cache. Here's what the default works out to on common disk sizes.

• 256 GB disk25.6 GB · Safe
• 512 GB disk51.2 GB · Safe
• 1 TB disk100 GB · Safe
• 2 TB disk200 GB · Safe

Calculated from Adobe's documented default of 10% of the volume where the media cache is located, using decimal gigabytes.

On a small internal disk, you may want a smaller limit than the default. On a large dedicated cache drive, the default is reasonable.

Which limit should you choose?

• Age suits short jobs. If you finish a project and rarely reopen it, a 30 or 60 day limit clears old work without touching current projects.
• Size suits small disks. A fixed limit stops the cache from crowding out everything else on a 256 GB or 512 GB Mac.
• Both can be on. The two options are separate settings, so you can cap by age and by size together.
• Off suits archival work. If you reopen old projects often and have a big cache drive, keeping everything saves rebuild time.

After Effects: media cache, disk cache and Empty All Caches

After Effects has two kinds of cache on disk. It shares the media cache with Premiere, and it keeps its own disk cache of rendered frames. Both are managed in After Effects › Settings › Disk, which older versions called Media & Disk Cache.

What is the disk cache?

As you preview, After Effects keeps rendered frames so it doesn't render them again. Adobe calls the version kept on disk the persistent disk cache: frames stay available even after you close a project or quit, and they're reused in any project that needs the same frames.

Blue bars in the Timeline panel mark frames cached to disk, and green bars mark frames cached in memory. The memory cache empties when you quit; the disk cache doesn't.

How big does the disk cache get?

Adobe says the default Maximum Disk Cache Size is 10% of the volume's total size, up to 100 GB. After Effects also checks that you have 10 GB free above the size you set, and warns you if there isn't enough room.

You choose the folder with Choose Folder. Adobe recommends a fast drive or SSD, separate from your source footage if you can, and notes the cache folder can't be the top level of a drive.

How do you empty it?

Click Empty Disk Cache in After Effects › Settings › Disk, or choose Edit › Purge › All Memory & Disk Cache, which clears the memory caches and the disk cache together. Adobe notes that purging the disk cache in one version of After Effects doesn't purge the cache of other versions.

There's also a broader option. In After Effects › Settings › Startup & Repair, Empty All Caches clears the disk cache, the media cache and the database cache. Adobe says it can free extra space and resolve certain startup issues.

What does Clean Database & Cache remove?

In the Conformed Media Cache section of the Disk settings, Clean Database & Cache removes conformed and indexed files from the cache, along with their database entries, but only for footage whose source file is no longer available. It's After Effects' version of Premiere's unused option.

Adobe's warning applies here too. Before clicking it, connect every drive with media you're using. Footage on a disconnected drive looks missing, so its cache files are removed and have to be conformed or indexed again later.

Command	Where	What it clears
Empty Disk Cache	Settings › Disk	Rendered frames on disk
Purge › All Memory & Disk Cache	Edit menu	Memory caches and the disk cache
Clean Database & Cache	Settings › Disk	Media cache for missing footage only
Empty All Caches	Settings › Startup & Repair	Disk, media and database caches
Empty 3D Cache	Settings › 3D	Cached data for imported 3D models

Media Encoder and the shared database

Media Encoder imports media too, so it creates the same conformed .cfa and .mpgindex files and writes them through the same database.

Where are Media Encoder's cache settings?

In the Media section of Media Encoder's settings. Adobe's page lists a location for Media Cache Files, with Browse to change it and the option to save cache files next to originals when possible, and a location for the Media Cache Database, with its own Browse and a Clean button.

Since the database is shared, changing its location here moves it for Premiere and After Effects as well.

What does Clean do in Media Encoder?

The same as in After Effects: it removes conformed and indexed files, and their entries, only for items whose source file is no longer available. Adobe repeats the warning to connect your media drives first.

Adobe also says Clean doesn't remove files for footage that's still available. To remove those, it says to go to the media cache folder shown in the Media settings and delete the files yourself, which is the manual route described above.

Why are there cache files next to my footage?

That's the Save Media Cache files next to originals when possible option at work. It keeps cache files with the media they came from, which helps when footage moves between computers on one drive.

The trade-off is that the cache is spread across your media drives. When you copy a footage folder to archive it, any cache files beside the footage are copied too. Like the rest of the media cache, they're recreated if the project is ever opened again.

Moving the media cache to another drive

If your internal disk is short of space, moving the cache is often better than clearing it again and again. Adobe recommends exactly that for performance anyway.

What does Adobe recommend?

Adobe's Premiere pages say to choose a fast SSD or NVMe drive for the media cache, ideally a dedicated one. Its storage recommendations describe three roles: a system drive for macOS and apps, a media cache drive for peak and conformed audio files, and a media drive for footage.

If you have only two drives, Adobe suggests keeping the media cache and the media on the same one. In shared environments, it says to keep the media cache on a local drive rather than on network storage.

Your drives	Where Adobe suggests the cache goes
One internal disk only	The internal disk, with a size limit
Internal disk plus one fast external	The external drive, with your media
Three drives	Its own dedicated SSD
Shared network storage for media	A local drive, not the network

How do you move the cache?

1. Connect the drive and create a folder for the cache on it.
2. In Premiere, open Premiere › Settings › Media Cache.
3. Click Browse next to the media cache files location, and choose the new folder.
4. Do the same for the media cache database, if you want both on the new drive.
5. Click OK, and restart Premiere.

In After Effects, the same choice is Choose Folder under Conformed Media Cache, and the disk cache has its own Choose Folder. Once the new location works, the old folders in Common can be moved to the Trash with the apps closed.

Which drive format should the cache drive use?

Adobe's media cache pages don't name a required format. Photoshop's documentation lists APFS and Mac OS Extended as the supported formats for its scratch disks on a Mac, which is a useful hint for any drive an Adobe app writes temporary files to. The post on APFS or exFAT for an external drive explains the trade-offs.

For a drive that only your Mac uses, APFS is macOS's own format. If the drive also has to work with a Windows PC, that changes the choice, and the format post covers it.

What else can go on that drive?

A fast external SSD can hold more than the cache: the footage itself, proxies, finished projects and archives. The post on freeing up space with an external drive covers what moves easily and what should stay on the internal disk.

Render previews, proxies and auto-saves: not the media cache

These are the files people most often delete by mistake, because they look like caches. They aren't in the Common folder, they don't rebuild by themselves the same way, and the catalog's media cache rule doesn't cover them.

Preview files, or render files

When you render part of a sequence, Premiere writes preview files, which Adobe describes as temporary render files created during editing to improve playback. They hold the results of effects, so the same section plays without being processed again. Premiere stores them in a folder you can specify, in the Scratch Disks settings of the project.

To delete them inside Premiere, make the Timeline panel active and choose Sequence › Delete Render Files for the whole sequence, or set the work area and choose Sequence › Delete Work Area Render Files. Adobe suggests deleting preview files to save disk space when you're completely done with a project.

Proxies

Proxies are low-resolution copies of your high-resolution footage, made for smoother editing. By default, Adobe says, Premiere adds _Proxy to each file's name and puts the proxies in a folder named Proxies next to the full-resolution clips.

Adobe itself warns that the default makes proxies hard to group or delete when you're done, because camera footage often sits in many separate folders. Choosing a single location with Choose Location keeps them together.

Is it safe to delete proxies?

Only when the project is finished and the full-resolution footage is safe. A proxy is a copy, so it can be made again from the original. But if the original is gone, a proxy may be the only version of that clip you have left. Treat proxy folders as project data and check before you delete.

Auto-saved project versions

Premiere saves your project automatically every five minutes and keeps the last 20 versions by default, in a Premiere Auto-Save folder. Adobe notes that this uses relatively little space, because project files are much smaller than video.

These are your project's history. They're worth keeping while you work, and the small amount of space they take isn't worth the risk of losing the version you need.

Item	Where it lives	Rebuilds itself?	How to remove it
Media cache	Adobe/Common in your Library	Yes	Media Cache settings, or Trash with apps closed
Preview files	The project's scratch disk folder	No, render again	Sequence › Delete Render Files
Proxies	A Proxies folder, or your chosen folder	Only from the originals	Trash, once the project is finished
Auto-saves	Premiere Auto-Save folder	No	Keep them; they're small
Disk cache	After Effects' chosen folder	Yes	Empty Disk Cache

Trimming a finished project with the Project Manager

For a finished project you want to keep, Premiere's File › Project Manager can consolidate it: it copies only the parts of footage used in the chosen sequences, with Exclude Unused Clips and handles you choose, and shows a disk space estimate first.

The result is a smaller copy of the project. Check it opens and plays before you remove the original footage. Deleting a project file never deletes its media, so the footage stays until you remove it yourself.

Mistakes to avoid, and a routine that works

Most problems with the Adobe media cache come from removing the wrong thing, or the right thing at the wrong moment.

Mistakes to avoid

• Deleting the folders while an Adobe app is open. Quit Premiere, After Effects and Media Encoder first, as Adobe's steps say.
• Cleaning with media drives disconnected. The unused and Clean options treat footage on a missing drive as gone and remove its cache.
• Deleting the whole Common or Adobe folder. Only the two cache folders are caches; the rest belongs to the apps.
• Removing preview files or proxies from an active project. They don't come back on their own, and proxies may be your only copy of a clip.
• Clearing Preferences to free space. The apps' settings are tiny and aren't caches.
• Expecting a faster Mac. Clearing frees space; projects open more slowly until the cache rebuilds.
• Forgetting the Trash. Space comes back only when you empty it, as the post on deleted files that don't free space explains.

A routine that keeps the cache in check

1. Turn on Automatically delete cache files older than in Premiere's Media Cache settings, with a number of days that fits how long your projects run.
2. If your internal disk is small, also set a size limit.
3. When a project is finished, delete its render files with Sequence › Delete Render Files.
4. Archive finished projects, with their proxies if you want them, to an external drive.
5. Once or twice a year, use Delete unused media cache files with every media drive connected.

Is this the only cache creative apps keep?

No. Photoshop writes large temporary scratch files while it works, and DaVinci Resolve keeps a render cache, optimized media and proxies of its own. The posts on Photoshop's scratch disk errors and DaVinci Resolve's cache and render files cover both.

For a broader view of what other apps keep, the post on clearing every cache on a Mac goes through the rest of your Library.

How the app does it

Wombit explains the media cache like everything else on the disk. Select Media Cache Files or Media Cache on the map, and the inspector says what they hold, that the apps rebuild them, and that the next project you open takes longer while they do. File names and paths never leave your Mac.

• ~/Library/Application Support/Adobe/Common/{Media Cache Files,Media Cache}

  Adobe media cache

  Conformed audio, peak and index files that Premiere Pro and other Adobe video apps create for imported media.

  Safe · Moves it to the Trash

Both folders are Safe, so they start checked in Cleanup and count in the headline number. If Premiere, After Effects or Media Encoder is open, the folders are left out and the review sheet offers to quit the app the way ⌘Q does; a cleanup never force-quits an app. Everything goes to the Trash, with Undo and Put Back.

Preview files, proxies and auto-saves sit in your project folders, which the catalog has no entry for, so they're never offered for removal. On a Mac with Apple Intelligence, the inspector can give a Best guess at what one is, labelled as a guess.

Finding and explaining the cache is part of the free analyzer. Cleanup is PRO: one payment of $4.99 with lifetime access. Every Pro tool's review is free to open, so you see what would go and why before you buy.