An AEP file serves primarily as an AE project blueprint 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 tiny even if the project uses gigabytes of footage.

Since the AEP relies on external links, After Effects may report "footage not found" whenever source files get moved, renamed, or omitted during a transfer, which is why the Collect Files feature (or manually assembling the AEP and all used media) is the normal way to send a project reliably, and if an AEP refuses to open in After Effects, hints like its source, companion files, Windows associations, or a quick read-only text-editor view can indicate whether it’s truly an AE project or an unrelated format.

When an AEP looks broken on another machine, it’s typically because it’s meant to point to external assets rather than include them, and After Effects stores absolute paths to footage, images, audio, and proxies, so if you move the project to a system with different directory names, drive mappings, or missing files, AE will open the project but show Missing/Offline Media until you relink the content.

A project may appear faulty despite having the footage if the new system is missing fonts—leading to text layout changes—or third-party plugins—causing effects to show as missing—or if an outdated After Effects version can’t process newer features, and the reliable remedy is to transfer via Collect Files or copy everything exactly as-is, then relink footage so that once fonts, plugins, and file paths align, the project usually resolves itself immediately.

An AEP file functions as a tightly packed project blueprint that holds your whole motion-graphics setup without storing footage, keeping comp details—resolution, frame rate, duration, nesting, and background—and all layers with transforms such as position, scale, rotation, opacity, blend modes, mattes, parenting, and timing, plus keyframes, easing, motion blur, markers, and expressions, as well as full effect stacks and mask/roto information including mask paths, feather, expansion, and animated points.

When 3D features are active, an AEP contains camera setups, light configurations, 3D layer parameters, and render options, as well as organizational metadata like bins, label colors, interpretation rules, and sometimes proxy info, but it typically excludes the footage—MP4s, MOVs, images, and WAVs are stored separately—so the AEP serves as the recipe and the pointers to those assets, meaning misplaced files trigger missing-media prompts For those who have almost any questions with regards to wherever in addition to the way to work with AEP file reader, you are able to call us from the web page. .