My 512GB MacBook was down to 9.92GB free.

Not "getting low." Not "maybe I should clean up soon." Nine point nine two gigabytes on a machine I use every day to build things. macOS was still running fine — that's the trap. It doesn't warn you until you're already in trouble.

I did what any reasonable developer would do at midnight: I opened a new project folder and started building.

The Problem

Disk cleaners exist. I've tried them. Most of them feel like black boxes — run a scan, get a scary number, click "Clean," and hope nothing breaks. Or they're bloated with upsells, subscription tiers, and features I never asked for.

What I actually wanted was simpler: show me what's hiding on my disk. The stuff macOS quietly accumulates over months and years that never shows up when you're just poking around Finder.

• Old dotfiles tied to apps you haven't used in years
• Massive node_modules folders from abandoned side projects
• Dormant app binaries and support data from software that's long gone
• Browser caches that grow without asking
• Local backups you forgot existed

It hides. It grows. And eventually you're sitting there with 9GB left on a 512GB machine wondering where it all went.

What MacPurity** Does**

MacPurity is the cleaner I always wanted but couldn't find. It surfaces all of that hidden junk — not as a vague "system cache" line item, but as real, inspectable categories you can review before deleting anything.

You scan. You see what's actually eating your disk. You decide what stays and what goes.

No subscription. No cloud upload. No "premium" tier to unlock the things that matter. Just an honest read on where your storage went, and a way to reclaim it.

One Overnight Build

I spent the night building. Shipped v0.1.0 the next afternoon. It runs, it scans, it works.

One overnight build later — my disk finally has room to breathe.

That's the part I love about building tools for yourself. The problem is immediate. The feedback loop is instant. You know within hours whether you solved the thing that was actually bothering you.

MacPurity started as a fix for my Mac. If your 512GB machine is quietly turning into a 500GB machine, it might be a fix for yours too.

Built in public — see the original post on X**.