An AEP file is the standard After Effects project format that outlines how your video is built rather than producing a playable export, capturing compositions, Layer elements of all types, animation data such as keyframes, effect setups, masks, mattes, plus cameras and lights in 3D space, and since it usually references media instead of embedding it, the AEP stays small even when the project draws on large external assets.
Because AEP files don’t embed footage, After Effects can throw "missing clips" 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 appears to "break" on another computer, it’s usually because it works as a blueprint that references outside files rather than storing them internally, meaning After Effects relies on absolute paths to footage, images, audio, and proxies, and once the project moves to a system with different drive letters, folder structures, or missing media, AE can open the project but not the assets, resulting in Missing/Offline Media until everything is relinked.
Projects may look "broken" even when footage is present if the new computer lacks the proper fonts—causing text to reflow—or is missing third-party plugins, which makes certain effects show as unavailable, or if you open the file in an older After Effects version that can’t interpret newer features, and the dependable fix is to move the AEP using Collect Files or copy the full project structure exactly, then relink footage so that once fonts, plugins, and paths match, the project usually fixes itself immediately.
In case you loved this article and you would want to receive details with regards to advanced AEP file handler assure visit our own internet site. An AEP file is a compressed structural database for AE so it can store an entire motion-graphics workflow while staying tiny, preserving comp settings—resolution, fps, duration, background, nesting—and all layers with transforms such as placement settings, scale, rotation, opacity, blend modes, mattes, parenting, timing, plus everything related to animation: keyframes, easing, motion blur, markers, and expressions, along with the full effect chain and mask/roto elements including mask paths, feather, expansion, and animated vertices.
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 pointers to your sources, which explains missing-media warnings when files get moved.