Where apps hide your files

Capture One catalogs, sessions and cache

Updated 2026-10-28 · 6 min read

Capture One does not hide its data. Catalogs and sessions go to your Pictures folder unless you picked another place, and the bulk of the disk space is a cache you can rebuild.

Default locations

~/Pictures/                      # default for new Catalogs and Sessions
MyCatalog.cocatalog              # a Catalog is one package
MySession/                       # a Session is a normal folder

Capture One's support pages say that unless you changed it, a Catalog or Session is created in the Pictures folder of the local drive. When you create a new catalog, Capture One recalls the location you chose last time, so if you once picked an external drive, new catalogs may offer that drive instead. Open Finder, choose Go > Go to Folder (⇧⌘G) and paste ~/Pictures.

Catalog or Session: know which you have

The two look different in Finder, and the difference decides where your images are.

• Catalog: a single .cocatalog item. It looks like one file but is a package, a folder macOS presents as a file. It holds the database, a cache and, depending on how you imported, the images themselves.
• Session: a regular folder containing a session database ending in .cosessiondb and sub-folders. A new session gets folders named Capture, Selects, Output and Trash. Captured and imported images go into Capture.

If you are not sure, look at the extension. A single item ending in .cocatalog is a catalog. A folder with a .cosessiondb file inside is a session.

Opening inside a catalog

Control-click the .cocatalog item and choose Show Package Contents. The items that matter:

Item	What it is
<name>.cocatalogdb	The catalog database: metadata and adjustments
Cache	Thumbnails (.cot) and previews (.cop), rebuilt on demand
Originals	Images stored inside the catalog, in year, month and day sub-folders

Originals only exists if you imported images into the catalog rather than referencing them. Browse in here freely, but do not rename, move or delete anything while Capture One is open.

Sessions keep their data beside the images

A session has no package. Instead, each folder that holds images gets a sub-folder named CaptureOne, and that is where the session keeps its data for those images:

MySession/Capture/CaptureOne/Cache/
MySession/Capture/CaptureOne/Settings<version>/

Cache holds thumbnails and previews. The Settings folder holds your adjustments, and Capture One's support notes that its name includes the version number. Keep the CaptureOne folder with the images whenever you copy them: it is what carries your edits to another Mac.

Originals: inside the catalog or referenced

When you import into a catalog, you choose whether Capture One copies the images into the catalog or leaves them where they are and references them. The choice matters when you back up:

• Stored inside: the catalog package contains your RAW files in Originals. Moving the package moves everything, and the package is large.
• Referenced: the catalog contains only data about the images. The RAW files stay in whatever folder you imported from, for example ~/Pictures/2026 Shoots/ or an external drive. Move the catalog and the images stay behind.

The quick check is the size of the package. A catalog of thousands of RAW files that is only a few gigabytes is referencing, not storing:

du -sh ~/Pictures/MyCatalog.cocatalog

The cache, and what is safe to delete

The cache is the largest thing you can safely remove. Capture One's support article on the Cache folder states that deleting it does not remove your images or adjustments; the app rebuilds thumbnails and previews the next time you browse, so the first browse afterwards is slower.

To clear it: quit Capture One. For a catalog, open the package with Show Package Contents and move Cache to the Trash in Finder. For a session, move the Cache folder inside each CaptureOne folder to the Trash. Delete nothing else. Never delete the .cocatalogdb file, the Originals folder, a Settings folder or the .cosessiondb file.

Moving a catalog or session

1. Quit Capture One.
2. In Finder, copy the whole .cocatalog package or the whole session folder to the new location.
3. If your catalog references images, copy those folders too, keeping their folder structure.
4. Double-click the copy to open it. Capture One may ask you to locate referenced folders that have changed path.
5. Open a few images to check, and only then move the old copy to the Trash.

For catalogs, Capture One also has its own backup: File > Backup Catalog. Capture One's support says it saves the database and adjustments but no original images, stores backups in Capture One's folder under ~/Library/Application Support by default, and that you can set a reminder and a different backup folder under Settings > General > Catalog Backup (Preferences on older macOS). Sessions have no built-in backup, so copy the session folder instead.

Settings and styles live elsewhere

Your styles, presets and workspaces are not in the catalog. They live in your user Library, in a folder named after Capture One under ~/Library/Application Support/, with styles in its Styles sub-folder. Confirm the exact folder name on your Mac with:

ls ~/Library/Application\ Support | grep -i capture

Back that folder up separately if you have spent time on styles and tool settings.

Why Spotlight cannot help

Spotlight treats a package as a single item, so it can show the .cocatalog itself but not the cache or Originals folder inside it. The styles folder is in ~/Library, which Spotlight does not show, and referenced images on an unplugged drive drop out of its results altogether.

Finding it when you forget where you put it

Catalogs and sessions default to ~/Pictures, and external drives are a common home for them too; macOS guards both, so give Everywhere Full Disk Access when it asks. Then typing cocatalog or cosessiondb lists every catalog and session on the Mac, including ones on drives that are not plugged in right now, and ⌘↵ reveals one in Finder. To track down a single RAW file inside a package, type its file name; Everywhere searches names only, not metadata or keywords.

Common questions

What is the default Capture One catalog location on a Mac?

The Pictures folder of your local drive, unless you chose another place when creating it. Capture One recalls the last location you used, so new catalogs may default to that one.

How do I see inside a Capture One catalog?

Control-click the .cocatalog file in Finder and choose Show Package Contents. You will see the .cocatalogdb database, the Cache folder and, if images were copied in, an Originals folder.

Is it safe to delete the Capture One cache?

Yes. Capture One's support says deleting the Cache does not remove images or adjustments, and thumbnails and previews are rebuilt when you next browse. Quit the app first and delete only the Cache folder.

Where are my RAW files if the catalog is small?

They are referenced, not stored. They remain in the folder or drive you imported them from, so moving the catalog alone will not move them.