An AET file generally refers to an After Effects master template, functioning as a reusable starter setup similar to an AEP but meant to be opened repeatedly without overwriting the original, so After Effects treats it like a master you open and then save as a new project, containing the full "recipe" for the animation—comps, timelines, layer stacks, keyframes, effects, expressions, cameras/lights, render settings, and organizational elements like folders and interpretations.

Should you loved this post and you want to receive details about AET file reader kindly visit our web-page. What an AET generally does not contain is the full media; instead it stores links or paths to footage, images, and audio kept elsewhere, which explains why templates are often zipped with a Footage or assets folder and why missing-file prompts appear if media was omitted, plus the fact that AETs can depend on certain fonts or plugins means opening them on a different computer may cause alerts until everything is installed, and since file extensions aren’t exclusive, verifying the file’s "Opens with" setting or checking its source location is the most reliable way to confirm its creator and needed companion files.

An AEP file serves as the primary file you update during animation, while an AET is a reusable template, so in practice the difference lies in purpose: you open an AEP to continue that same project, but you open an AET to start a fresh file so the original stays clean.

That’s why AETs are frequently relied on for packaged motion-graphics templates such as intros, lower-thirds, and slideshows: the creator keeps the AET as the master and each time a new video is needed you open it, immediately Save As a new project (becoming your own AEP), then swap text, colors, logos, and media, and although both formats can store the same project elements—comps, layers, keyframes, effects, expressions, cameras/lights, and settings—and both usually reference external footage, the AET is built to protect the master for repeatable work while the AEP serves as the editable file you keep updating.

An AET file retains the structure and animation logic of an After Effects project but not always the media assets, containing compositions with defined resolution, FPS, duration, and nesting, plus the complete layer arrangement—text, shapes, solids, adjustments, precomps, and placeholders—with layer properties like position, scale, rotation, opacity, masks, mattes, blending modes, parenting, and the project’s animation data including keyframes, easing, markers, and any expressions used to automate motion.

On top of that, the template remembers all effects and their settings—color correction, blurs, glows, distortions, transitions, and more—along with any 3D setup such as cameras, lights, 3D layer properties, and render/preview settings, plus project-level organization like folders, label colors, interpretation rules, and sometimes proxies, but it typically does not bundle full footage, images, audio, fonts, or plugins, instead keeping links and dependencies that may trigger missing-asset or missing-plugin warnings on another computer until everything is relinked or installed.