What are media cache files?

When importing video and audio into Adobe After Effects, it processes versions of these files that it can readily access for faster performance. These are referred to as "media cache" files. These are stored in the Media Cache Files folder. In addition, there is a folder containing a database, which retains links to each of the media cache files. These are referred to as "media cache database" files. They are located in the Media Cache folder.

Note: there is a delay in proper audio and video playback while newly imported media is being processed and cached. A progress bar in the lower right of the application shows the progress of the media cache being processed.

Where are these files stored?

Sometimes, these cache folders get too large, or contain a corrupt file, so you need to know where to locate them for deletion. By default, both the cache files (in the Media Cache Files folder) and the media cache database files (in the Media Cache folder) are stored in these locations:

Mac: /Users//Library/Application Support/Adobe/Common

Windows: \Users\<username>\AppData\Roaming\Adobe\Common

NOTE: By default, AppData is a hidden folder. Check this tutorial on how to access it: How to Find the AppData Folder in Windows 10 - YouTube

You can change the media cache location under Preferences > Media Cache in After Effects

How to clean media cache files?

Open any After Effects project and navigate to the toolbar at the top of your screen to select Edit > Purge > All Memory & Disk Cache...

You'll be shown a dialogue box that allows you to choose if you want to clear the disk cache for all versions, or if you only want to clear for the current version of After Effects. This is helpful if you have multiple versions of After Effects downloaded on your machine.

After deleting the files, you should see additional hard drive space become available, as the media cache files can take up significant space. If you have older projects you have completed, it is a good idea to delete these files to save storage space and to keep your computer's hard drive tidier.

Keep in mind that a delay also occurs after you delete all cache files and then open a current project as the files need time to rebuild. If you have a large project, budget enough time for the media cache files to rebuild. This can be done overnight, for example.