An AEP file is used by After Effects to store project structure 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 lean regardless of how large the external media is.

Because AEP files don’t embed footage, After Effects can throw "footage not available" 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 loads without footage on a second computer, the reason is usually that it’s a blueprint referencing outside media instead of embedding it, and After Effects uses absolute file paths for video, images, audio, and proxies, so once the project is moved to a machine with mismatched paths—different drives, folder names, or missing files—AE can load the structure but not the assets, yielding Missing/Offline Media until relinking.

Projects may look messed up even when footage is present if the new computer lacks the proper fonts—causing text to shift—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.

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.

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 assembly instructions and the file paths of the sources, causing missing-media alerts if items are moved or renamed If you enjoyed this article and you would certainly such as to get more info regarding AEP file structure kindly browse through the website. .