Every feature, in detail

Scanner speed and accuracy

The scanner walks the filesystem with getattrlistbulk(2) across a worker pool — one syscall returning a batch of directory-entry attributes at once, instead of a stat per file. On an M2 Pro (release build, warm cache), a full home-folder scan covered 4,473,939 entries — 3,625,939 files and 848,000 directories, 464 GB — in 38.1 seconds, about 3× faster wall-clock than du -sk on ~/Library alone (51s).

Hard-link–aware deduplication means shared blocks are never double-counted: files that share the same device/inode pair (Time-Machine-thinned backups, cloned app resources) are flagged and counted once, not once per link. Every size is also available in both apparent (logical) and on-disk (allocated) form, so you can see what a file actually costs you.

Massive Disk scans network volumes, is aware of Full Disk Access — scans still work without it, but protected folders (Mail, Safari data, other apps' containers) are reported as inaccessible rather than silently skipped — and surfaces every denied folder explicitly instead of pretending it doesn't exist.

Method: M2 Pro, release build, warm cache. Home-folder scan (Massive Disk, 4,473,939 entries) vs. du -sk on ~/Library alone (51s) — a smaller subset of the same home folder, not the identical target. du -sk doesn't report an entry count, so this is a wall-clock comparison, not a throughput one; Massive Disk's own rate works out to roughly 117,000 entries/sec. A plain find with no stat call finishes in 10.9s but collects no size or type information.

Six visualizations, one scan

Every visualization reads the same scan tree, so switching between them (⌘1–⌘6) never costs a rescan. Hover any node for a tooltip, drill into a folder with a double-click or Return, right-click for a context menu, or drag a file straight out to the Finder. Colour by category, depth, or size — and any active highlight filter tints matching nodes orange, in every view.

Inspector and category legend

Select anything and the Inspector fills in: icon, name, a copyable path, size in both logical and allocated form, item count, modified and created dates, and category. A composition bar breaks any folder down by category — "what the colours mean" at a glance — and lists the top 10 largest items inside it. Every selection offers Quick Look, Reveal in Finder, Open, Copy Path, and Open in Terminal, all included free.

Highlight filters

Turn on any combination and matching files light up orange across whichever visualization you're in — a fast way to see exactly how much of your disk a category of clutter really occupies before deciding what to do about it.

Cleanup queue and safety

Add anything to the cleanup queue from the Inspector or a right-click, review the full list and total size in the cleanup bar, then send it to the Trash. Nothing is ever deleted permanently — every removal goes through the Finder's own Trash. The queue is ancestor-aware: stage a folder and something inside it, and only the folder is trashed, so nothing fails or gets double-counted. Anything on a protected system path triggers the System File Warning gate — a sheet naming the reason it's flagged — and requires an explicit "Delete Anyway" before it proceeds.

That gate reflects a broader principle: every removal goes to the Trash, so a mistake is always recoverable. That's why Massive Disk has no shredder and no permanent delete, anywhere in the app. The same caution extends to the Applications uninstaller below — endpoint security and MDM agents such as CrowdStrike, SentinelOne, Jamf, ESET, and Cisco Secure Client are never offered for uninstall, the same way Apple's own system apps aren't.

Space Savers — Pro

A curated registry of exactly where Macs quietly fill up: developer tool and package-manager caches, build artifacts, old backups, and files nobody's opened in months. Every finding is measured, tagged with a safety tier, and one click from the Trash — or, where a specialized tool does the job better (Homebrew, pnpm, Docker, Go, Time Machine), a ready-to-run command instead.

What it looks like

The full registry

Every kind Space Savers looks for, grouped the way the app groups them:

Duplicates — Pro

Finds byte-for-byte identical files in three phases — group by size, then a partial SHA-256 of the first 64 KB, then a full SHA-256 — so nothing is ever flagged as a duplicate on a coincidence. Groups are sorted by wasted space; "Stage all extras" keeps the first copy of each group and queues every other copy for the Trash in one click.

Applications uninstaller — Pro

Lists every installed app with its full footprint, then hunts down what a drag-to-Trash leaves behind: Application Support, Caches, Preferences, Saved State, Containers, Group Containers, HTTP storage, WebKit data, Logs, Launch Agents, Launch Daemons, Application Scripts, cookies and installer receipts — not just the .app. Apple's own system apps are protected from removal, and so is a dedicated protected-app list: endpoint security and MDM agents — CrowdStrike, SentinelOne, Jamf, ESET, Cisco Secure Client and similar — are never offered for uninstall, full stop. An app that's currently running is flagged before you can uninstall it. The riskier leftovers — Launch Agents, Launch Daemons, and Group Containers, which can be shared across a whole vendor's app family — are listed but never checked by default.

Snapshots — Pro

Capture the shape of any scan, then compare it against a later one to see exactly what grew, what shrank, and what disappeared. The comparison threshold is adjustable (10 MB by default) so tiny noise doesn't drown out real changes, and a change that's fully explained by a change in one of its ancestors — a folder that only grew because a file inside it grew — collapses into that parent row instead of being listed twice.

Quick Search (⌘F)

A Spotlight-style overlay that understands both file metadata and your current scan tree. Type naturally and it parses type, size and time filters straight out of the query:

Results carry size, path and modified date, and are openable, revealable, or Quick-Look-able without leaving the keyboard.

System Monitor

A live dashboard of what your Mac is doing right now: CPU load, memory pressure, network throughput, power draw and battery health, and the top processes actually responsible for each — included free.

Privacy

Massive Disk reads your filesystem locally and stops there. There are exactly two kinds of outbound network request in the entire app: checking your Pro subscription status, and checking whether a newer version is available. No analytics, no crash reporting, no third-party SDK riding along in the background — your file names, paths and sizes never leave this Mac.

Native Apple Silicon

Built with SwiftUI for Apple Silicon, arm64 only, macOS 14 (Sonoma) or later — no Electron, no Rosetta. The download is small, updates ship through Sparkle so you're never stuck waiting on an App Store review, and every release is signed with a Developer ID certificate and notarized by Apple.