Choose File > New Catalog.
When you create a catalog, you create a folder for it, too. The name of the folder is the same as the name of the catalog, without the catalog suffix. For example, if you name the folder "Wedding Photos," the catalog file will be "Wedding Photos.lrcat". When you add photos to the catalog, Lightroom Classic creates a preview cache file (such as "Wedding Photos Previews.lrdata") and puts it in the folder with the catalog.
Choose File > New Catalog.
Specify the name and location of the new catalog folder, and then click Save (Windows) or Create (Mac OS).
Lightroom Classic resets and displays an empty Library module, ready for you to import photos.
When you open a different catalog, Lightroom Classic closes the current catalog and relaunches.
Choose File > Open Catalog.
In the Open Catalog dialog box, specify the catalog file and then click Open.
You can also choose a catalog from the File > Open Recent menu.
If prompted, click Relaunch to close the current catalog and relaunch Lightroom Classic.
You can also change general preferences to specify which catalog opens when Lightroom Classic starts. See Change the default catalog.
You can open, or import, a catalog from an earlier version of Lightroom Classic, including a beta version, in a more recent version of Lightroom Classic. When you do, Lightroom Classic upgrades it. The new, updated catalog contains all of the metadata associated with the previous catalog and photos.
Start Lightroom Classic for the first time.
If you've opened Lightroom Classic previously, choose File > Open Catalog.
Navigate to the old catalog .lrcat file, and then click Open.
If you can't remember where the old catalog is located, search for "lrcat" in the Explorer (Windows) or Finder (Mac OS).
If prompted, click Relaunch to close the current catalog and restart Lightroom Classic.
(Optional) In the Lightroom Catalog Upgrade dialog box, change the name of the upgraded catalog. By default, the catalog will be named as <currentCatalogName>-v10.
The option to provide a name for an upgraded catalog is available in Lightroom Classic 10.0.
If you want backward compatibility, keep the old files (files not containing - in their names). You can delete the old files when you don't need the backward compatibility.
Before copying or moving a catalog and preview files, back them up.
Locate the folder that contains the catalog and preview files. In Lightroom Classic, choose Edit > Catalog Settings (Windows) or Lightroom Classic > Catalog Settings (Mac OS).
In the Information area of the General panel, click Show to go to the catalog in the Explorer (Windows) or Finder (Mac OS).
Quit Lightroom Classic.
In the Explorer (Windows) or Finder (Mac OS), copy or move the catalog.lrcat, Previews.lrdata, and (if present) Smart Previews.lrdata files to the new location.
Double-click the .lrcat file in the new location to open it in Lightroom Classic.
(Optional) If Lightroom Classic can't find folders or photos in the copied or moved catalog, a Question Mark icon appears by folder names in the Folders panel and an Exclamation Point icon appears in photo thumbnails in the Grid view. To restore folder links, right-click (Windows) or Control-click (Mac OS) a folder with a Question Mark icon and choose Find Missing Folder. To relink individual photos, see Locate missing photos.
You can create a catalog that contains a subset of a larger catalog by selecting the photos and exporting them as a new catalog. This is useful when, for example, you import photos into a catalog on a laptop and then later add them to a master catalog on a desktop computer.
Choose File > Export As Catalog.
Indicate whether you want to export the negative files and previews, and then click Save (Windows) or Export Catalog (Mac OS).
"Negative files" refers to the original files that were imported into Lightroom Classic.
The new catalog contains links to the selected photos and their information. You must open the new catalog to view it.
Deleting a catalog erases all the work you've done in Lightroom Classic that isn't saved in the photo files. While the previews are deleted, the original photos being linked to are not deleted.
Using the Explorer (Windows) or Finder (Mac OS), locate the folder that contains your catalog and drag it to the Recycling Bin (Windows) or Trash (Mac OS).
Important: Make sure that the folder you delete contains only the catalog files you intend to erase, and not additional files.
To enhance performance, Lightroom Classic builds a Previews folder next to the .lrcat file in the Explorer (Windows) or Finder (Mac OS). It is safe to delete this folder as long as its name matches the .lrcat file name. If you delete a Previews folder that's still needed by a catalog, Lightroom Classic will regenerate it when you work in that catalog, but it will run more slowly until the previews are rebuilt.
By default, Lightroom Classic opens the most current catalog at startup. This behavior can be changed to opening a different catalog or to always prompting you to choose a catalog.
Choose Edit > Preferences (Windows) or Lightroom Classic > Preferences (Mac OS).
In the General tab, choose one of the following from the When Starting Up Use This Catalog menu:
Load Most Recent Catalog
Opens the most recent catalog you've been working with.
Prompt Me When Starting Lightroom
Opens the Select Catalog dialog box at startup so you can choose.
A catalog in the default location
Lightroom Classic lists all of the catalogs in \Pictures\Lightroom (Windows) or /Pictures/Lightroom (Mac OS) for you to choose.
Allows you to navigate to a specific catalog file (.lrcat) and select it as the default catalog to open at startup.
You can specify many preferred behaviors for Lightroom Classic catalogs in the Catalog Settings dialog box.
Choose Edit > Catalog Settings (Windows) or Lightroom Classic > Catalog Settings (Mac OS).
In the General tab, specify any of the following:
Provides information such as the location, filename, and creation date of the catalog. Click Show to view the catalog file in Explorer (Windows) or Finder (Mac OS).
Lets you specify the frequency with which the current catalog is backed up. See Back up a catalog.
In the File Handling tab, specify any of the following:
Determines how Lightroom Classic renders three types of image previews. All previews are stored in the preview cache file in the folder where your catalog is located.
Standard Preview Size
Specifies the maximum length, in pixels, of the long side of full-size rendered previews. Choose a size that is equal to or larger than your screen resolution. For example, if your screen resolution is 1920 x 1200 pixels, choose Standard Preview Size > 2048 Pixels. If your screen resolution exceeds 2048 pixels, Lightroom Classic generates a 1:1 preview instead.
Specifies the appearance of the thumbnail previews. Low, Medium, and High are similar to the quality scale for JPEG images.
Automatically Discard 1:1 Previews
This setting specifies when 1:1 previews are discarded based on the most recent access to the preview. 1:1 previews have the same pixel dimensions as the original photos, and show sharpening and noise reduction. They are rendered as needed and can make the catalog preview file large, so it's good to discard them periodically.
Indicates how much disk space is being used by Smart Previews. For information on using Smart Previews, see Smart Previews.
Import Sequence Numbers
Specifies starting sequence numbers for photos as you import into the catalog. Import Number is the first number in a series that identifies how many import operations are performed. Photos Imported is the first number in a series that identifies how many photos have been imported into the catalog. See The Filename Template Editor and Text Template Editor.
In the Metadata tab, select any of the following:
Offer Suggestions From Recently Entered Values
When you start typing a metadata entry that resembles a previous entry, one or more suggestions appear as you type. Deselect this option to turn it off. Click Clear All Suggestion Lists to clear previous entries.
Include Develop Settings In Metadata Inside JPEG, TIFF, PNG, And PSD Files
Deselect this option to prevent Lightroom Classic from including Develop module settings in the XMP metadata of JPEG, TIFF, PNG, and PSD files.
Automatically Write Changes Into XMP
Select this option to save metadata changes directly to the XMP sidecar files, making the changes visible in other applications. Deselect this option to save metadata settings only in the catalog. For information on saving XMP changes manually, see About metadata and XMP.
Enable Reverse Geocoding of GPS Coordinates To Provide Address Suggestions
Allows Lightroom Classic to send your photo's GPS coordinates, if available, to Google so that Lightroom Classic can determine the city, state, and country of the photo and add that information into the IPTC Location metadata.
Export Reverse Geocoding Suggestions Whenever Address Fields Are Empty
If selected, Lightroom Classic includes Google-suggested IPTC Location metadata in photos when you export them.
Write Date Or Time Changes Into Proprietary Raw Files
This option controls whether Lightroom Classic writes a new date and time to proprietary raw files when you use the Metadata > Edit Capture Time command to change a photo's capture time metadata. By default, this option is not selected.
After you have imported, edited, and perhaps removed a number of files, Lightroom Classic may run slower. When that happens, optimize your catalog to improve performance.
Choose File > Optimize Catalog.