.MCAT File Extension

An MCAT file is a catalog file created by Adobe Lightroom, a photo editing and management application. It contains information used to label and organize photos you've imported into Lightroom. MCAT files are not meant to be opened.

When you import one or more photos into Lightroom, the program creates an MCAT file named Managed Catalog.mcat. This file is a SQLite 3 database that contains metadata associated with your photos. Lightroom uses this metadata to organize your photos. The MCAT file also contains references to where your photos are stored, as well as the edits you've made to each photo.

Lightroom also creates an additional MCAT file, stored in the program's profiles directory. This file contains metadata about Lightroom Profiles, which users can apply while editing photos.

MCAT files are not meant to be manually opened.