An AEP file is normally used as an After Effects project definition that contains the instructions for building your composition rather than a finished movie, including timelines, multiple layer types, animation data like expression-driven changes, effect parameters, masks, mattes, and 3D components such as cameras and lights, while referencing external media files to stay compact even if the project uses gigabytes of footage.
This is why After Effects may show “missing footage” when source clips are moved, renamed, or left behind after transferring only the AEP to another computer, and to avoid this you usually rely on the Collect Files feature (or manually gather the project plus all linked assets into one folder) so everything reconnects properly, and in the rare case an AEP isn’t actually from After Effects, checking where it came from, what files sit next to it, what Windows reports under “Opens with,” or even skimming it in a text editor can reveal whether it’s a real AE project or a different format altogether.
When an AEP seems to go “broken” on a different PC, the cause is almost always that it functions as a reference-based blueprint instead of a self-contained package, with After Effects saving absolute file paths to video, images, audio, and proxy files, and when the project lands on a machine where those paths don’t match due to new drive letters, folder differences, or absent assets, AE loads the project but reports Missing/Offline Media until you reconnect the files.
Projects can seem incorrectly loaded even with all footage available when the new PC doesn’t have the right fonts, causing text to shift unexpectedly, or lacks third-party plugins so effects appear missing, or when an older version of After Effects can’t read newer project elements, and the stable solution is to use Collect Files or duplicate the exact folder structure and then relink, after which matching fonts, plugins, and paths typically restore the project instantly.
An AEP file is basically a compact internal database that can represent a full motion-graphics project without the storage weight of footage, containing comp attributes like resolution, frame rate, length, nesting, and background, all timeline layers and their transforms such as position, scale, rotation, opacity, blending, track mattes, parenting, timing, plus animation instructions including keyframes, easing curves, motion blur, markers, expressions, effect parameters, and mask/roto data like contour shapes, feather, expansion, and animated points.
If you use AE’s 3D tools, the AEP includes your camera data, lights, 3D-layer properties, and related render settings, along with project details like folder organization, labeling, interpretation values, and proxy entries, but the media itself—videos, images, and audio—remains outside the file, making the AEP mainly the project definition plus the addresses to your sources, which explains missing-media warnings when files get moved If you enjoyed this post and you would certainly such as to get additional facts relating to AEP file description kindly visit our webpage. .
