An AEP file serves as the blueprint for an AE project instead of being a final video, holding compositions, layer stacks, animation items like keyframes and expressions, effects with adjustable settings, masks, mattes, and 3D objects like cameras or lights, and it typically stores only links to the actual footage so the file itself stays light regardless of how large the external media is.

Because AEP files don’t embed footage, After Effects can throw "offline media" warnings if you relocate or rename the assets or copy only the AEP to another computer without its media, making Collect Files—or manual gathering of all referenced items—the safest way to move a project, and if an AEP won’t open in AE, details such as where it originated, what’s stored beside it, Windows’ "Opens with," or a quick text-editor look can reveal if it’s a standard AE file or something from another software vendor.

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.

Sometimes a project appears "broken" even though the footage is there if the new PC is missing fonts—triggering text reflow—or lacks third-party plugins, disabling certain effects, or if a newer AEP is opened in an older AE version, and the proven fix is transferring via Collect Files or copying the entire folder tree, then relinking so that once fonts, plugins, and media paths line up, the project typically un-breaks right away.

An AEP file acts as a condensed structural 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 placement values, 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 outline paths, feather, expansion, and animated points.

When you use 3D tools, an AEP stores your camera setups, lighting, all 3D-layer attributes, and any render settings tied to them, along with project-organization info like folders, label colors, interpretation rules, and sometimes proxy links, but it generally doesn’t embed media—MP4s, MOVs, images, and WAVs remain separate—so the AEP holds the project logic and the addresses of the sources, causing missing-media alerts if items are moved or renamed If you loved this article and you would such as to obtain even more facts relating to AEP format kindly go to our web page. .