Sunburst
Directory levels become rings. Each segment's area is proportional to the bytes it allocated. Five levels deep.
macOS 14+ · Mac App Store
Your disk,
Your disk,
at a glance.
Sundial turns a crowded folder into a map you can read. Scan a directory, spot what is taking the room, and move the files you no longer need to the Trash. The numbers are honest, the controls are native, and your data stays on your Mac.
Universal binary · Apple silicon and Intel · App Sandbox
Private by default
Three ways to read the same tree
Built for macOS
One scan. Three readings.
Allocated byteswhat the volume actually gave up
Live resultsfolders appear while the scan runs
Private by defaultno network calls, no telemetry
Read the same scan three ways
Each view reads the same scan. Click a folder to open it, click a file to select it. The breadcrumb walks back up.
Blocks
A treemap. The same proportions as the sunburst, packed into rectangles, which is easier to compare at a glance.
List
The file browser using the whole window. It is present in every other view too, and it is the one that reads correctly to VoiceOver.
A disk tool should tell the truth
Sundial is careful about what it counts, when it refreshes, and what happens when you press Trash.
Results before the scan finishes
The first folders appear while the scan continues, down to three levels, with deeper contents aggregated until the full tree arrives. If a previous scan exists, its entry count drives the progress estimate.
The second scan is the fast one
Sundial saves the folder tree and an FSEvents cursor. The next refresh re-reads only the folders macOS reported as changed. If macOS cannot prove the event history is complete, it does a full scan instead of guessing.
Allocated bytes, counted once
Sizes are allocated bytes, which is what the volume actually gave up, not file length. The scanner stays on one volume, skips symbolic links, and counts a hard-linked file once.
It says what it could not read
Unreadable paths show up in a banner with the error, and the totals then describe only what was measured. A failed or incomplete refresh never replaces a complete saved scan.
Trash that measures first
Deleting measures the item on a worker thread, then asks. Files go to the macOS Trash, so you can put them back. After a delete, overlapping saved scans are invalidated and the affected roots are rescanned to reconcile hard links.
Sandboxed by design
Sundial runs under App Sandbox with access only to the folder you picked. Bookmarks are not persisted, so it asks again after a relaunch. A saved measurement is not an access grant.
Built for the keyboard
The native list is the accessible representation of both visuals. Its rows announce name, type, and size, and expose selection, opening, Reveal, and Trash. The canvas drawings are hidden from the accessibility tree so the browser is not read out twice.
| ↑ ↓ | Select a row |
| → | Expand the selected folder |
| ← | Collapse it, or move to its parent |
| Return | Open the selected folder |
| ⌘↑ | Go to the parent folder |
| ⌘⇧R | Reveal in Finder |
| ⌘⌫ | Measure, confirm, then move to Trash |
What it does not claim
A disk tool that overstates what it measured is worse than no tool.
- The Trash confirmation reports a measurement snapshot, not guaranteed reclaimed space. The filesystem can change under the operation.
- Unaccounted space on a whole-volume scan can include snapshots and purgeable space. It is a difference, not a list of files you can delete.
- The list shows up to 200 entries per folder. A remainder row reports the omitted count and bytes. Visuals also drop regions too small to draw.
- Whole-volume coverage has not been validated under every macOS permission setup. Full Disk Access is a separate grant from the folder picker.
Get Sundial
Sundial runs on macOS 14 and later, on Apple silicon and Intel.
Requirements
macOS 14 or later. Universal binary for Apple silicon and Intel. Roughly 6 MB.
Sandboxed and reviewed
Sundial ships through the Mac App Store. It runs in the App Sandbox and reads only the folder you give it.
Your files stay yours
Sundial reads only the folder you pick, does no network calls, and sends no telemetry. It has nowhere to send your file names. Read the privacy policy.
Under the hood
Swift + SwiftUI
The interface, the scanner, the layouts, and the cache are all Swift. No third-party dependencies.
Atomic cache
Each cache file stores its metadata and tree atomically. Invalid records are ignored and rebuilt rather than trusted.
Tested before it deletes
The Trash path, the cache, and the scanner each have their own suite, and every build runs them. A tool that moves your files to the Trash has to earn that.