What is the standard file format for After Effects project files?

The standard file format for After Effects project files is AEP. This format is the default for saving your projects in Adobe After Effects, allowing users to store compositions, layers, and other project-related assets in a single file. AEP files are structured to retain all the animation, effects, and timeline information required to recreate the project when reopened within After Effects.

In contrast, AEF and AEPR are not recognized file formats associated with After Effects. While AEPX is an alternative format, used for saving projects in a more XML-friendly way that can be useful for version control and text editing, it is not the standard file format for general use. The AEP format remains the primary choice for most users for its direct compatibility and ease of use within the application.