What is a photo catalog?

The short answer

A photo catalog is a searchable index of your photos. For each photo it keeps a small thumbnail, a larger preview, the metadata and a pointer to where the original file sits. Photo cataloging software, a kind of photo organizing software, is the app that builds and searches this index.

The originals stay in your own folders, on your own drives. Because the previews live in the catalog, you can browse and search with the drive unplugged. Find the photo first. Then plug in the one drive that holds it.

Photo catalog vs photo library

The difference is where the photos live. A photo library app imports your photos, copying them into a library it manages, on your computer or in cloud storage. A photo catalog leaves the files where they are and keeps a record of them.

Libraries are simple, with one place to look. Catalogs suit archives already sorted into folders, or spread across external drives you don't want to reorganize.

What is a catalog in Lightroom Classic?

A Lightroom catalog is how Adobe Lightroom Classic keeps track of your photos. Lightroom Classic catalogs photos stored on internal or external drives, and photos can also sit on a network drive. Your original files stay on your own drives.

What Adobe says, as of October 2026:

• Edits live in the catalog. Lightroom Classic edits nondestructively and never changes your photos' image data. By default, edits and metadata are stored in its catalog rather than in the files.
• Writing to files is optional. If you choose to, it can write metadata into JPEG, TIFF, PSD and DNG files, and into sidecar files for raw formats. It's off by default.
• No network drive for the catalog. Adobe says the catalog can't be stored on a network drive, though the photos themselves can be.
• Unplugged drives still show. Per Adobe, imported photos still appear, and can be searched, on that computer when their external drive is disconnected. Smart Previews let you keep editing, and the edits apply to the originals when you reconnect the drive.
• Phones see synced collections. To see Classic photos on a phone, you add them to synced collections, and they appear in Adobe's separate Lightroom mobile app through Adobe's cloud.

Lightroom Classic is a full photo editor plus a catalog. It offers full keyword, EXIF, IPTC and XMP metadata support, and it filters by keywords, camera and lens data. According to Adobe, it also includes facial recognition (its People view).

Lightroom catalogs and CachePix

CachePix doesn't read Lightroom catalogs (.lrcat), collections, develop edits, star ratings or color labels. RAW previews come from the camera's embedded JPEG, so your Lightroom edits to RAW files don't show.

It does read the keywords, captions, titles, people, city and state Lightroom writes to JPEG and TIFF files, or to XMP sidecars next to RAW files, once you turn that writing on. Edit in Lightroom Classic, then search the same folders in CachePix on your computer, or by people, keywords and caption on your phone. More on CachePix and Lightroom Classic.

Disk catalog vs photo catalog

A disk catalog records the files and folders on each drive, of any type, and lets you search that list with the drive unplugged. It answers one question well: which drive holds this file?

A photo catalog is built around photos. Its job is to show you the picture and what's in it: previews you can view full screen, and the metadata (people, keywords, captions, places) that describes each shot.

The line blurs, since some disk catalog apps also read photo metadata.

For named apps on both sides, checked against their makers' sites, compare photo catalog software.

CachePix is a photo catalog. It catalogs JPEG, PNG, WebP and 15 RAW formats (CR2, CR3, NEF, NRW, ARW, SR2, RAF, ORF, RW2, DNG, PEF, SRW, X3F, IIQ, 3FR). HEIC and TIFF photos are cataloged and searchable, and previews for them are coming. Video isn't supported.

How to catalog photos on your computer

These steps work with most catalog apps.

1. Sort the folders first. Use one scheme on each drive, such as year folders with dated event folders inside, and do big moves before you catalog. Here's how to organize photos on an external hard drive.
2. Put names and captions in the files. Write them as IPTC and XMP metadata, so any app that reads those standards can use them. More on how to search by keywords and captions.
3. Point the catalog at your folders. It builds thumbnails and previews without copying the photos anywhere. Check how much disk space the previews will take.
4. Back up the photos and the catalog. A catalog isn't a backup (more below).

Photos show as missing when the location a catalog recorded no longer matches, usually because a folder moved or a drive was renamed. Once a drive is cataloged, keep its name and folder layout stable. On Mac, CachePix tracks each drive by its volume ID, so a renamed drive re-links the next time you connect it.

Cataloging with CachePix

CachePix is a photo catalog app for Mac and Windows. It catalogs the photos on your drives, then syncs a searchable catalog to free iPhone and Android companion apps, so you can browse your archive with the drives unplugged. Your photos never go to the cloud.

1. Install CachePix on your Mac or Windows computer and sign in with the code we email you.
2. Connect a drive. In Drives & Folders, choose Catalog a Folder… and pick a folder or the drive itself. There's no import.
3. Check the estimate. CachePix generates previews for about 24 sampled photos and estimates the preview store's size before you start.
4. Let it run in the background. Cancel any time and the work so far is kept.
5. Unplug and search by filename, people, keywords, caption, city, event and more.
6. Optional: open Pair Phone…, click Turn On and scan the QR code with your phone. The catalog syncs one way, from your computer to your phone, over your local network.

Cataloging never modifies, moves, renames or deletes your files. CachePix writes metadata only when you edit it, and only the fields you changed, as standard XMP in the file or in a sidecar next to RAW files.

Your photos, previews and catalog never leave your own computer and phone. CachePix's only online service is your account: email sign-in, the plan check, and Stripe billing in your browser.

You need a Mac with Apple silicon (M1 or later) on macOS 12 or later, or 64-bit Windows (x64). Download CachePix, or see the photo cataloging software features.

Is a catalog a backup?

No. If a drive fails, a catalog can tell you what was on it, but it can't give you the originals back.

The Library of Congress's personal archiving advice is a good baseline: make at least two copies, store them in different places, check them at least once a year, and make new copies on new media every five years, or sooner when needed.

Back up the catalog too. In CachePix, open Storage & Backup… and choose Back Up to write a timestamped catalog snapshot, optionally with previews.

Keep reading

More in all guides.

• Organize

  How to organize photos on an external hard drive

  Folders, drive names, two copies and a catalog.

• Compare

  CachePix vs Lightroom Classic

  Edit in Lightroom Classic, browse on your phone.

• Metadata

  Search by keywords, captions and names

  The fields that help you find photos.

Adobe facts last checked October 6, 2026.