For macOS 26 · Apple Silicon
A native macOS disk-usage visualizer in the WinDirStat lineage - rebuilt in Swift 6, SwiftUI, and Metal. Cushioned squarified treemap, honest APFS clone accounting, GPU hit-testing, AppIntents. The Mac tool we wished existed.
files mapped in one zoomable picture
seconds to scan your entire Mac
fake gigabytes from double-counting
What It Does
Most Mac disk visualizers are aging cross-platform Qt apps or shareware that hasn't been updated since Mojave. Delve is what happens when you rewrite the genre from scratch in Swift 6, with 2026 HIG chrome and all the modern Apple plumbing.
The Bruls/Huijgen/van Wijk algorithm, faithfully ported and rendered in Metal. Recursive surface accumulation gives every nested folder real depth - the WinDirStat-class look, finally on Mac, at 60 Hz across two million tiles.
Built on getattrlistbulk, the canonical macOS bulk-stat syscall - 3-5× faster than the standard API. A full APFS volume in under 90 seconds.
A second render pass writes instance IDs per pixel. Hover anywhere - instant precise selection, no spatial index needed.
The treemap fills in as the scan progresses. No 90-second blank screen. The UI stays interactive the entire time.
ScanFolder, FindLargestFiles, FindFilesByExtension - surfaced in Spotlight and Shortcuts automatically.
Hit space on any selected file. Native preview right inside the inspector - no detour through Finder.
A live histogram of every extension on the volume, sorted by total bytes. Click .psd, see every Photoshop file ranked by size. Full regex over the tree, too. No other Mac app bundles both.
The Treemap
Each rectangle is a file. Its area is its size. Its color is its extension. Nested folders cushion-shade into 3D so hierarchy is visible at a glance. Hover anything for instant detail. Click to drill in. Trust the picture.
We rejected the radial-gradient fake. The recursive surface accumulation is what conveys hierarchy depth - losing it loses the visual.
Honest Accounting
APFS clones share storage. Hardlinks share storage. Most Mac tools double-count them, then quietly tell you you'll recover gigabytes you won't actually get back. Delve shows logical size and on-disk size side by side, and never lies about either.
(dev_t, fileID) - zero after. No phantom storage.SF_DATALESS flag detected. We tag with a cloud glyph and never accidentally materialize a file just to read its size.Apple-Native, Top to Bottom
Swift 6 strict concurrency. SwiftUI shell with NavigationSplitView and Inspector. Metal 3 renderer that extends under the toolbar so Liquid Glass has something to refract. Semantic colors, SF Symbols, real document windows. The kind of polish you only get from a from-scratch native app.
SwiftUI DocumentGroup with a custom .delve-scan UTType. Scan two volumes side-by-side in Stage Manager. Save, reopen, share with a teammate.
The treemap is the secondary surface. The tree list is fully navigable with custom rotors - "Largest items," "By extension," "By depth."
AppIntents register on first launch. Ask Spotlight "find largest files in Downloads" - Delve answers, no app launch required.
Installed copies poll appcast.xml, offer updates via Check for Updates… or a daily background check. EdDSA-signed, notarized.
Privacy
Delve needs Full Disk Access to do its job - every byte on your disk is the whole point. None of it leaves your computer. None of it touches a server. We don't have a server.
Full Disk Access is a TCC grant, not an entitlement. You decide. We show one explainer sheet with a deep link to System Settings and stay out of your way.
We use anonymous app analytics - version, OS, crash counts. We never send a file name, path, hash, or extension breakdown. Your filesystem is none of our business.
Hardened runtime, Developer ID signed, Apple-notarized. Sparkle update bundles are EdDSA-signed with a key that lives in the macOS Keychain on one machine.
Delve itself is proprietary - but the architecture doc, the perf plan, and the analytics conventions are all public. No black boxes about how it works.
Questions
DaisyDisk uses a sunburst diagram and fudges APFS clones. GrandPerspective is a great app that hasn't fundamentally changed in two decades. Delve is a from-scratch native rewrite of the WinDirStat-style cushioned treemap with honest clone accounting, GPU hit-testing, AppIntents, regex search, an extensions panel, and 2026 macOS chrome - features that, taken together, no Mac app currently bundles.
Delve relies heavily on UMA (unified memory architecture) - the renderer reads the scan arena directly from Metal shared storage without copying. That's an Apple Silicon thing. We could ship an Intel build that's slower and uses more memory, but we'd rather build the best version of the app for the hardware most Mac users have today.
The App Store requires sandboxing, and a sandboxed app can't see most of your disk - which defeats the entire purpose. Delve ships Developer ID + notarized, direct download, with Sparkle 2 for in-app updates. Same security level the App Store gives you, without the lobotomy.
Yes, for any folder outside your home directory. macOS will silently skip protected locations otherwise. Delve detects this on first launch and shows a one-time explainer with a deep link straight to the right System Settings panel. After you grant access, macOS quits the app and we relaunch cleanly.
Under 90 seconds for a full 1 TB APFS volume with a few million files, on an M2. We use getattrlistbulk(2), the canonical bulk-stat syscall, which is 3–5× faster than NSFileManager. The treemap fills in as the scan progresses - you're not staring at a blank window.
Dataless cloud stubs are detected via the SF_DATALESS flag. We show their logical size (what they'd take if materialized) and on-disk size (the ~3 KB stub) separately, with a cloud glyph. Delve never accidentally materializes a file just to read its size.
Yes. Every feature, no paywall, no trial. We may add a paid pro tier later for power-user cleanup workflows, but everything that ships today stays free forever.
The full architecture document is in the repo under design/delve-architecture.md. Scanner, renderer, data model, persistence, cleanup actions, analytics conventions - all there. Read it before filing an issue.
Get It
Direct download. Developer ID + notarized. Sparkle handles updates from here on out.
macOS 26+ · Apple Silicon · Free · Developer ID + Notarized · Sparkle auto-updates