An AET file is primarily a template version of an AEP, letting users open it and save a fresh project each time to preserve the template, and it contains the full design of the animation—compositions, timelines, layer structures, keyframes, effects, expressions, cameras, lights, render settings, along with organizational components such as folder layouts and interpretation rules.
What it usually doesn’t include is the raw media itself; instead it keeps references or paths to external footage, images, and audio, which is why templates are often delivered as a ZIP with an assets/Footage folder and why you’ll see missing-file prompts if items were left out or not synced, and because AETs may rely on specific fonts or third-party plugins, opening one on another machine can trigger warnings until everything is installed or relinked, with the final reminder that although AET typically means an After Effects template, file extensions aren’t exclusive, so checking "Opens with" in file properties or recalling where the file came from is the safest way to confirm what program created it and what extra files it should include.
An AEP file is the standard save file for ongoing AE work, whereas an AET is a template designed for reuse, meaning you open an AEP to keep working on that same animation but open an AET to create a new copy without modifying the master template.
That’s why AETs are commonly chosen 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.
For more information on AET file download review our website. An AET file mostly keeps the structure and logic of a motion-graphics project but not necessarily its media, holding compositions with their resolution, FPS, duration, and nesting order, and keeping the full layer stack—text, shapes, solids, adjustments, precomps, and placeholders—plus each layer’s settings such as position, scale, rotation, opacity, masks, mattes, blending modes, and parenting, along with all animation info including keyframes, easing curves, markers, and any motion-driving expressions.
Additionally, the template captures effects and their configurations, such as color correction, blurs, glows, distortions, and transitions, together with any 3D setup—cameras, lights, 3D layer settings—and render/preview preferences, plus project structure like folders, labels, interpretation settings, and proxies, though it usually omits embedding raw media, fonts, or plugins, depending on linked paths that can lead to missing-footage or missing-effect warnings when the file is opened elsewhere.