Katmora draws your disk as a map, with each file shown as a tile sized by the space it takes. It runs entirely on your Mac and has no internet access.

Contact

Questions, problems or suggestions: [email protected]. Please include your macOS version and, if something went wrong, what you did just before it happened.

Requirements

macOS 14 or later, on Apple silicon or Intel Macs. Available in English, Turkish, German, French, Spanish, Italian, Portuguese (Brazil), Japanese, Korean and Simplified Chinese.

Frequently asked questions

How do I map my whole startup disk?

Open the Full Disk Access guide on the start screen. It has two steps: turn on Katmora in System Settings › Privacy & Security › Full Disk Access, then choose Macintosh HD with Select Disk. Katmora cannot turn this setting on by itself. To map a single folder or an external drive, choose it directly; no extra setting is needed.

Can I try it without giving any access?

Yes. “Explore a demo disk first” on the start screen opens a sample disk. It reads no files. The Review Basket and Identical Files are not available there, because they work on real files.

Why is Katmora’s total different from what macOS reports?

macOS reports how much of the disk is used; Katmora adds up the files it could read. The difference, usually local snapshots, data macOS can remove on its own when space is needed, other system volumes and folders macOS protects, is shown as a separate “Measurement difference” in the summary, not as a tile on the map.

What does “Size unknown” mean?

Katmora could not read that folder, usually because macOS protects it. Its size is shown as unknown instead of zero.

Does Katmora delete files?

Never by itself. It moves an item to the Trash only after you confirm, and nothing is deleted until the Trash is emptied. Undo (⌘Z) puts back the last item or the last Review Basket batch until you rescan or quit.

Identical Files shows a group with a small or zero repeated size. Why?

Copies that share storage on disk, such as APFS clones, do not take the space twice, so that space is not counted as repeated. Removing such a copy may free little or no space.

How do I find a file by name?

Press ⌘F and type part of the name. Matches appear as you type, largest first, and light up on the map. Several words must all match; * and ? work as wildcards, for example *.mov.

Privacy

Katmora collects no data. Read the Katmora privacy policy.

Katmora: Disk Space Map