Meowtenance finds the build caches, simulator data and app junk that pile up on a Mac developer's disk, shows you what each one actually costs, and lets you choose what goes — down to the individual project.
Version 2.1 · macOS 14 Sonoma or later · Apple Silicon and Intel · Signed and notarised by Apple · No account, no telemetry.
Measured on one iOS developer's Mac on 28 August 2026. These are real numbers from a single machine, not an average — your Mac will look different. The free version shows you your own numbers before anything is deleted.
| What | Why it survives | Size |
|---|---|---|
| SwiftUI Preview cache | Each preview device copies ~650 MB of system data | 7.13 GB |
| Xcode DerivedData | Build output across 9 projects | 4.32 GB |
| Simulator symbolication | Inside each simulator, cleanable without deleting the device | 3.44 GB |
| User caches | Never pruned by anything | 2.58 GB |
| In-app web caches | Electron apps: Figma, VS Code, Slack… | 1.28 GB |
| Xcode documentation cache | Re-downloads on demand | 0.92 GB |
| Everything else | Logs, diagnostics, crash reports, package caches | 8.49 GB |
| Simulator devices | Listed separately — deleting one removes the whole device | 22.80 GB |
| Reclaimable | 50.96 GB |
DerivedData holds two very different things. Build output regenerates in minutes. Swift Package checkouts have to come back over the network — and on a slow connection that is the difference between a coffee and an afternoon.
Meowtenance deletes the first and keeps the second. Not just inside DerivedData:
the shared SwiftPM cache in ~/Library/Caches is protected too, so a
general cache sweep can't quietly undo it.
Global SwiftPM cache left untouched on the machine measured above — bare git clones and binary artifacts that would otherwise be re-fetched.
Every project in DerivedData is its own row with its own size. Clear the two you finished last year, leave the one you are working in today.
Most cleaners report what they intended to delete. Meowtenance measures the folder again after deleting, compares, and reports the difference.
If another app was holding files open — editors, sync clients and background builds do this constantly — you get "partially cleaned" and the name of the category, not a green checkmark over 2 GB that never went anywhere.
The app opens with every checkbox empty. It never decides for you what is disposable.
Privileged deletion is limited to a fixed list compiled into the app. macOS shows its own password dialog; the app never sees, stores or transmits your password.
The optional heuristic scan can surface junk nobody predefined. Those items are moved to the Trash, never deleted outright, so you can put them back.
The app makes no network requests of its own, collects nothing, and needs no account. Everything happens on your machine.
One-time purchase. No subscription, no licence server, no account.
Find out what you'd get back.
Pay once. Yours for good.
The free version is ready — the checkout isn't. Version 2.1 is signed and notarised by Apple, so it opens without warnings. Download it and see your own numbers; it scans and reports everything but deletes nothing. Payment for the full version is being set up and opens shortly.
While the app deletes and re-scans, a cat grooms itself. It is drawn from scratch in one of twelve art movements, chosen at random — impressionism, cubism, pop art, constructivism and nine more — with the pool weighted so you keep seeing new ones.
Every cat, and the app icon, is original vector art generated by the app itself. No stock assets, no third-party illustrations, no licensed fonts.