What is taking up the disk: a cushion treemap of every file, each as big as the space it takes. It is Disk Inventory X by Tjark Derlien (gitlab.com/tderlien/disk-inventory-x) rewritten in Swift for today's Macs: native on Apple Silicon, and much faster. The S stands for Swift.
Free software and freeware: GPL 3, no ads, no tracking, no accounts.
Disk Inventory S exists thanks to Disk Inventory X by Tjark Derlien (source), which since 2003 has shown Mac users what fills their disks, and which he released as free software under the GPL. Its treemap, with the cushion shading of van Wijk and van de Wetering, its colors and its idea of looking at a whole disk at once are all his; this rewrite only tries to make them fast on today's Macs. Thank you, Tjark.
This is a modified version, not the author's: rewritten by Riccardo Di Paola in 2026 (the GPL asks to say so). The treemap layout and drawing come from the original's TMVItem.m and TMVCushionRenderer.m; scanning, model and interface are new. Please report problems here, not to the original author.
Requires macOS 15 or later, on Apple Silicon or Intel.
Download the .dmg from Releases and drag
the app into Applications. The first time, macOS says it cannot verify the developer: the app is
not signed with a paid Apple Developer ID. Open System Settings › Privacy & Security, scroll
down and click Open Anyway (once per version). The source is all here, if you want to check.
Or with one Terminal command, which skips that step (files downloaded with curl are not
quarantined):
curl -fsSL https://raw.githubusercontent.com/dipa84/disk-inventory-s/main/install.sh | zsh
Or build it yourself (see Building below).
To read everything, give it Full Disk Access (System Settings › Privacy & Security › Full Disk Access): it then reads Mail, Messages and the other private folders without asking for each one.
| Disk Inventory X (one thread, NSURL) | Disk Inventory S | du -sk |
|
|---|---|---|---|
| /Applications, 600,000 files | 158 s | 3.9 s | 21 s |
| home folder, 1.2 million files | 723 s | 15.5 s | 103 s |
| whole disk, 3 million files | — | 34 s | — |
(M1, 8 cores.)
- The scan reads each folder with
getattrlistbulk(many entries per call, with name, type and sizes together) on all cores; sums and sorting happen in parallel as folders finish. - Hard links and APFS clones count only once. The original (and the Finder) count each clone in
full: on a disk holding the copies Chrome leaves in
/private/var/foldersit came to more than three times the disk. - Volumes mounted inside the folder are not traversed; firmlinks are (as in the original).
- The treemap is the same (TMVItem and TMVCushionRenderer), drawn in bands on all cores.
| click | selects the file |
| double click | goes into the folder under the pointer |
| ← → ↑ ↓ | the neighboring tile, at the same level |
| ⇧ and the arrows | the neighboring tile, at the level of the folder above |
| ⌘↑ / ⌘↓ | selects the enclosing folder / the largest entry inside |
| ↩ | goes into the selected folder |
| ⌘[ / ⌘] / ⇧⌘[ | goes out one level / back in / the whole folder |
| space, ⌘Y | Quick Look |
| ⌘R | Show in Finder |
| ⌥⌘C | copies the path |
| ⇧⌘R | rereads the selected folder from disk |
| ⌘⌫ | moves to the Trash (asks first) |
Selecting a file kind in the list at the bottom highlights it in the treemap.
When reading a whole disk, the treemap also shows entries that are not files:
- Free Space: what is still available (purgeable space can be added in the settings, but it counts twice the iCloud files that are also in the treemap);
- System Volumes: the other volumes of the same APFS container (virtual memory, Preboot,
Recovery, updates), measured one by one with
diskutil apfs list; - Folders Not Read: the space of the folders an app cannot open. System ones (the Spotlight
index, document versions,
/private/var/db…) belong to root: the button at the bottom of the window has the helper (dis-cli export, inside the app) read them with the administrator password, read-only, and puts them in the treemap with their names. Private ones (Mail, Messages…) need Full Disk Access; - File System Data: once everything was read, what remains (APFS indexes and tables).
Reading “/” also reads the data volume (/System/Volumes/Data), skipping the folders the firmlinks
lead to, already counted from “/”: some things live only there, like macOS Install Data.
The original put all of this into a single “Other space”.
General (size, decimal or binary units, Trash confirmation, what to open at launch, language), Map (cushion relief and light, lines between files, frame under the pointer, 12 or 24 colored kinds), Scan (clones and hard links once, other volumes, packages, folders to skip), Space.
English, Italian, Spanish, French, German, Simplified Chinese, Japanese. The strings live in
tools/translations.py, which writes the .strings files and stops if the code passes a string to
L() without a translation. File kind names come from macOS, in the app's language.
The command line tools (Swift 6) are enough; Xcode is not needed.
tools/make-certificate.sh # once per Mac: a local signing certificate
tools/build-app.sh # .build/Disk Inventory S.app
tools/build-app.sh --install # also into /Applications
swift run -c release dis-tests
swift run -c release dis-cli scan ~ # scan timings
The local certificate keeps macOS privacy permissions from one build to the next: signed ad hoc, every build looks like a new app to macOS, which asks for them again.
DIS_TIMING=1 prints scan and drawing times; DIS_PHOTO=file.png saves an image of the window
after the scan and quits (DIS_ACTIONS=selectChild,zoomIn runs menu actions first).
GPL 3, like Disk Inventory X (COPYING).