CAPX file is a archive file compressed using ZIP format. CAPX file extension was developed by the creators of Construct software, a tool that allows uesr to create 2D computer games for various system platforms. CAPX archive contains all files that compose give game project, including audio files and graphics.

CAPX are stored along with CAPROJ files, which are used for opening the project after unpacking the archive. CAPX files enable users to easily store and share projects in form of single file archive.