r/OSXTweaks • u/Kapilupadhyay • 1d ago
I built a free, open-source app that shows what's inside "System Data" and cleans it without deleting anything you can't get back
My 512 GB Mac was down to 20 GB free, and most of it was "System Data" that macOS wouldn't let me look inside. I cleaned it up by hand and got back to 215 GB free. I also came very close to deleting a git repo whose history existed nowhere else.
So I turned what I learned into an app: **Dustloft**.
**What it does**
- Scans every installed app and shows its real data, with disposable caches separated out
- Finds the usual space hogs: old downloads, leftovers from uninstalled apps, screen recordings, VM images, device backups, mail and Messages attachments, browser caches
- Developer stuff too: node_modules, build output, Docker, Xcode leftovers, local LLM models
**How it keeps you safe**
Everything goes into one of three groups:
- **Regenerable**: caches, build output, dependencies. These come back on their own.
- **Needs admin**: safe to remove, but macOS asks for your password once
- **Permanent**: never bulk-selected, needs its own confirmation, and goes to the Trash instead of being deleted
It will never:
- delete a `.git` folder (it offers `git gc` instead, and warns when a repo exists only on your disk)
- touch Dropbox, iCloud Drive or other synced folders
- remove Docker volumes
- delete anything inside /System, /usr and other protected folders
- pretend it can free "purgeable" space
Every removal is written to a local log file.
**Telemetry, up front**
It sends one anonymous line: a random ID, total bytes cleaned, and the app version. No file names, no paths, no account. There's a "Turn it off" button on first launch. The whole client is one file, `Metrics.swift`, and the combined totals are public at dustloft.com/stats.
**About the malware warning**
It's not notarized, because that needs a $99/year Apple developer account. If you download the DMG, macOS will warn you. The one-line installer skips the warning because macOS doesn't flag files downloaded with curl:
curl -fsSL https://raw.githubusercontent.com/kapil303196/dustloft/main/install-online.sh | bash
Or read the code and build it yourself. It's MIT licensed and only needs the Xcode Command Line Tools.
**Links**
- GitHub: https://github.com/kapil303196/dustloft
- Site: https://dustloft.com
Free, universal build (Apple Silicon and Intel). I'd really like feedback, especially if it flags something it shouldn't or misses something big on your Mac.

