Today’s Question: Is it safe to delete old catalogs (>2 years old) from Lightroom Classic?
Tim’s Quick Answer: Yes, it is safe to delete old and outdated catalogs with (of course) a few caveats.
More Detail: In general, it is safe to delete old Lightroom Classic catalogs that are out of date. I will share, however, a few caveats.
First, an old catalog should only be deleted if you have a current catalog that is in use and that supersedes the old catalog. For example, if the old catalog is an earlier version of your current catalog and you have the current catalog backed up, you can absolutely delete the old catalog files.
I also recommend enabling the option to save metadata to the source images, so that even if you lost your catalog and all backup copies, you would still have key metadata such as star ratings and keywords attached to the source images. To enable this option go to the Metadata tab of the Catalog Settings dialog and turn on the “Automatically write changes into sidecar files (XMP/ACR)”.
In addition, I recommend confirming that the old catalog is actually an old version of your current catalog. I would want to be sure, for example, that the old catalog isn’t a different catalog that might contain images that are not reflected in your primary catalog.
It is worth noting that the older an outdated catalog (or catalog backup) is, the less valuable it is likely to be. If you lost your current catalog and the only backup was from two years ago, there’s a good chance that it would be easier to start over with a new catalog rather than restoring an old catalog and trying to get it updated to reflect all newer photos and metadata.
