DiskX — macOS disk space analyzer & disk explorer

The WizTree-fast, ncdu-friendly disk visualizer macOS never shipped. A free, open-source disk space analyzer for Mac that shows what's eating your storage — and, unlike every other disk usage analyzer, tells you what's actually safe to delete first.

If you've ever searched "what is taking up space on my Mac", "how to free up disk space on macOS", "what is System Data", or "find large files Mac" — this is the tool that answers it in one screen. DiskX is a native Swift/SwiftUI storage analyzer, disk explorer and disk cleaner for macOS 14+ (Apple Silicon and Intel), combining a treemap visualization, a keyboard-driven file browser, and safe one-keystroke deletion.

Every existing analyzer sorts by raw size, which puts /System and your Photos Library — the things you cannot or should not touch — at the top, while the 40 GB of Xcode caches you could delete right now sits three levels deep. DiskX's default ordering answers the question users actually ask: "What should I delete first?"

Download

⬇ Download DiskX 1.0.3 (.dmg) — macOS 14 Sonoma or later, universal.

1.0.3 is the notarized build of the 1.0.2 security release, which fixes a reproducible crash that let any scanned folder abort the app and hardens the deletion path. Update from 1.0.0/1.0.1/1.0.2.

Drag it to Applications and open it. No right-click → Open, no xattr, no Privacy & Security detour: it is Developer ID signed, notarized by Apple, and stapled — both the DMG and the app inside it, so first launch works offline too. Gatekeeper reports source=Notarized Developer ID.

Prefer to build it yourself? See Build & run — it takes about ten seconds.

Highlights

• Reclaim Sort (default): rows ordered by reclaimable bytes × safety tier × staleness — deterministic, inspectable, never AI. The displayed number is always honest gigabytes, never an abstract score. Every row has a plain-language WHY line ("Xcode cache — regenerates on next build · untouched 14 months · frees 21.3 GB now").
• Ghost-row hoisting: deep junk (DerivedData, node_modules, …) is hoisted into the current level as ↳ …/Xcode/DerivedData · 6 levels deep — no repetitive drill-down.
• Truth Bar: honest capacity accounting that reconciles with Finder — scanned files, "Other & System" (the System Data mystery, explained), purgeable, free. Plus "Reclaimable now: ~X safe" and a freed-this-session counter.
• WizTree-class scanning: parallel getattrlistbulk work-stealing pool; hard links deduped by inode; live streaming results — never a blank wait.
• 100 % keyboard: ↑↓/jk move · →/Return descend · ←/⌘↑ up · X mark across folders · Space QuickLook · 1–5 sorts · ` flat Top-Files view · G goal mode ("I need 25 GB back") · ? cheat sheet.
• Fear-free deletion: select 1–n items → Delete → a keyboard-first confirm sheet. Return or Y confirms, Esc or N cancels. Risk-proportional friction: if everything regenerates, one Return suffices; if anything is yours, Return goes inert and an explicit Y is required. Trash-only (never permanent), app-level ⌘Z restores the whole batch. Protected system items can never enter the flow.

DiskX vs. the alternatives

DiskX exists because we read thousands of user reviews and forum threads about the tools below and built around what people kept asking for. If you're comparing Mac disk space analyzers, here's an honest summary — including where the others are genuinely better.

Tool	Platform	Price	Approach	Where DiskX differs
DiskX	macOS 14+	Free, open source	Treemap + keyboard list, reclaim-first sorting	Sorts by what's safe to delete, not raw size; 100 % keyboard; Trash-only with undo
DaisyDisk	macOS	~$10 one-time	Beautiful sunburst chart, drag-to-collector deletion	DaisyDisk's sunburst is gorgeous and it's genuinely fast; DiskX trades it for an area-accurate treemap, keyboard-only operation, and explicit "safe to delete" reasoning
CleanMyMac	macOS	Subscription	Automated one-click cleanup suites	CleanMyMac automates far more (malware scan, uninstaller, maintenance); DiskX only analyzes and deletes what you pick, with no subscription, no telemetry, no background agents
Disk Inventory X	macOS	Free	The classic treemap that inspired this category	Disk Inventory X is effectively unmaintained and slow on modern multi-TB disks; DiskX is a native, parallel, Apple Silicon rewrite of the same idea
GrandPerspective	macOS	Free (GPL)	Long-lived, well-maintained treemap	GrandPerspective is a great free treemap; DiskX adds labeled rows, reclaim scoring, keyboard navigation and safer deletion
OmniDiskSweeper	macOS	Free	Finder-style size-sorted column browser	OmniDiskSweeper is very fast and very simple, but it deletes permanently and shows no visualization; DiskX always routes through the Trash and is undoable
WizTree / TreeSize / WinDirStat / SpaceSniffer	Windows	Free / paid	The Windows gold standard for fast scans	These don't exist on macOS — DiskX is the answer to "I wish there were a WizTree for Mac"
ncdu / dust / gdu	Terminal	Free	Blazing keyboard-driven TUIs	DiskX keeps ncdu's keyboard efficiency and its delete-with-confirm flow, in a native GUI with a treemap
macOS Storage Settings	Built in	Free	High-level category bars	The built-in panel famously can't explain "System Data"; the DiskX Truth Bar reconciles scanned files, system, purgeable and free space so the numbers add up

Common search terms this project answers: mac disk space analyzer · disk usage analyzer macOS · disk explorer Mac · treemap disk visualizer · find large files on Mac · free up storage on MacBook · what is System Data on Mac · delete Xcode DerivedData · clean node_modules · Disk Inventory X alternative · DaisyDisk alternative · WizTree for Mac · ncdu GUI · open source Mac disk cleaner.

Build & run

swift build            # debug build
swift test             # engine tests
Scripts/package_app.sh # → DiskX.app (reads version.env)
open DiskX.app

Grant Full Disk Access (System Settings → Privacy & Security) to scan ~/Library and system paths — DiskX shows an honest "unreadable" chip instead of silently undercounting.

App Store edition

The Mac App Store build is sandboxed: DiskX scans only locations you grant via the folder picker (persisted as security-scoped bookmarks), starting from a welcome screen instead of an automatic Home scan. Ship checklist:

1. Apple Developer Program membership; create an app record in App Store Connect with the bundle id from version.env.
2. Certificates: Apple Distribution + 3rd Party Mac Developer Installer; a Mac App Store provisioning profile saved as Entitlements/DiskX.provisionprofile.
3. Build the upload package:

   APP_IDENTITY="Apple Distribution: <Team>" \
   INSTALLER_IDENTITY="3rd Party Mac Developer Installer: <Team>" \
   Scripts/package_appstore.sh        # → DiskX-<version>.pkg

4. Upload with Transporter.app, then fill in screenshots/description/privacy ("Data Not Collected" — the app has no telemetry).

Already handled in-repo: App Sandbox entitlements (Entitlements/DiskX-AppStore.entitlements), privacy manifest with required-reason API declarations (PrivacyInfo.xcprivacy), app icon (Icon.icns), category/copyright/hi-res Info.plist metadata, and sandbox-aware scanning (AccessManager). Direct distribution (Developer ID + notarization, no sandbox) keeps full-disk scanning: Scripts/notarize_release.sh builds a universal binary, signs it with the Developer ID identity under the hardened runtime, then notarizes and staples both the .app and the DMG.

Appearance

Light, dark, and system themes — Settings (⌘,) → Appearance. All UI uses semantic colors and Liquid Glass (macOS 26+) with material fallbacks, so both modes are first-class.

Architecture

Target	Contents
DiskXCore	ScanSession (getattrlistbulk pool) · ReclaimAnalyzer (tiers, staleness, hotspots) · TreemapLayout (squarified) · TrashEngine (trash-only, minimal cover) · FileNode (lock-guarded live tree)
DiskX	SwiftUI app: AppModel (single brain), global KeyboardDispatch, views
diskx-bench	CLI scan benchmark

How it was built — the AI orchestration pipeline

DiskX was developed end-to-end in one session by a multi-agent orchestration framework: three deterministic workflows fanning out 48 specialized agents (~3.3M tokens), coordinated by a main loop that owned the architecture, integration, and verification.

flowchart LR
    subgraph W1["Workflow 1 — Research & Design (9 agents)"]
        R1["4 pain-point researchers<br/>(Disk Inventory X, DaisyDisk,<br/>WizTree/ncdu, user wishes)"] --> J
        R2["1 macOS tech researcher<br/>(getattrlistbulk, APFS, sandbox)"] --> J
        C["3 UX concept designers<br/>novice-first · keyboard-first ·<br/>visualization-innovation"] --> J
        J["Judge panel:<br/>scores concepts, synthesizes<br/>DESIGN-SPEC.md"]
    end
    subgraph M["Main loop (inline)"]
        A["Engine + AppModel contracts<br/>scanner · treemap · trash · analyzer"]
    end
    subgraph W2["Workflow 2 — Implementation (6 agents, parallel)"]
        I["file list · treemap · truth bar ·<br/>confirm sheet · chrome · QuickLook<br/>— disjoint files vs pinned API"]
    end
    subgraph W3["Workflow 3 — Adversarial Review (33 agents)"]
        F["5 dimension finders:<br/>deletion safety · scanner ABI ·<br/>concurrency · keyboard UX · perf"] --> V
        V["28 independent skeptic verifiers<br/>(one per finding, briefed to refute)"]
    end
    W1 --> M --> W2 --> W3 --> X["Main loop: fix all 28<br/>confirmed findings, package,<br/>benchmark, ship"]

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1. Research & design — five researchers swept reviews, Reddit, and HN in parallel for the pain points of every existing disk analyzer (22 tool findings, 59 explicit user wishes), while a tech agent mapped the fastest scanning APIs. Three designers then produced competing concepts from different angles, and a judge agent scored them and synthesized the final design spec — the origin of Reclaim Sort, the Truth Bar, ghost-row hoisting, and risk-proportional deletion.
2. Parallel implementation — the main loop first wrote the core engine and pinned the AppModel API as a contract, then six agents implemented the SwiftUI modules concurrently, each owning disjoint files and verifying its own diagnostics. Integration and build fixes stayed in the main loop.
3. Adversarial review — five finder agents attacked orthogonal dimensions; every single finding was handed to an independent verifier instructed to refute it. 28 findings survived (0 refuted) — including six criticals like firmlink double-counting and a cursor/selection desync — and all 28 were fixed and re-verified before packaging.

The engine was additionally validated headlessly: 14 unit/integration tests (including a real Trash round-trip) and a benchmark scanning 1.33M files in 45s (~29,000 files/sec) — 2.4× faster than du on the same tree, with the reclaim analysis over the whole tree taking a further 1.2s.

Links

• Website: https://avantigroupai.github.io/diskx-web/
• Releases: https://github.com/avantigroupai/DiskX/releases
• Design spec: docs/DESIGN-SPEC.md

License

Not yet licensed for redistribution — all rights reserved for now. If you want to use DiskX in your own project, open an issue.

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