Today’s Question: Can (or should) old Lightroom Classic catalog files be deleted?
Tim’s Quick Answer: Yes, I do think that older catalog files should be deleted to avoid confusion and clutter, and to some extent to free up hard drive space. The only additional consideration is how soon those older catalog files should be deleted.
More Detail: In Lightroom Classic it is critically important to ensure you’re always working with the correct version of your catalog. In general, I recommend that photographers only use a single catalog to manage their photos with Lightroom Classic, so that basically means always working with the most recent catalog.
Over time you will also accumulate “extra” copies of your catalog, such as when the catalog file needs to be updated for a new version of Lightroom Classic. That was the case with the upgrade to Lightroom Classic version 11, for example. When your existing catalog is upgraded from version 10 to version 11, you’ll end up with a new catalog for version 11 but the existing catalog from version 10 will remain.
You will also accumulate multiple backup copies of your Lightroom Catalog, assuming you’re using the built-in catalog backup feature, which I strongly recommend making use of so that your catalog can be checked for errors and optimized as part of that backup process.
When it comes to deciding when to delete older catalogs, I recommend trying to find a balance between the potential utility versus the potential for confusion. For example, even if I were to completely lose all recent copies of my Lightroom Classic catalog, I don’t imagine I would ever want to recover from a backup that was created ten years ago. There would be so much recent information missing from that catalog that recovering from it wouldn’t be of much help.
I generally consider any catalog more than about one year old to be of minimal value to a photographer who is actively capturing new images. So, in general I would say it probably makes sense to delete catalogs that are older than about one year.
Of course, it is also a good idea to be somewhat conservative when deleting files that have potential value. Therefore, you might consider an intermediate step of moving files that could be deleted to an archival storage location. For example, as soon as a catalog is updated for a new version of Lightroom Classic you could move the previous version files to an archive folder. The backup copies of the catalog should also not be stored in the exact same folder as the current catalog (by default they are stored in a “Backups” folder within the folder that contains the catalog).
The key is to avoid confusion about which catalog is your “real” catalog, to avoid clutter related to your catalog, and to avoid consuming hard drive space unnecessarily. As long as your current catalog is working properly and you have several backup copies, older files can certainly be deleted or at least archived.