Xcode's attic
DerivedData, Archives, and old simulators can swallow 50+ GB without a single warning.
Where the gigabytes hide
node_modules sprawl
Every project carries its own universe. Multiply by clients times years.
Invisible images
Docker.raw, VM disks, and container layers live outside your home folder, where Finder never looks.
The workflow
Scan the whole volume
Home-folder scans miss the whales in ~/Library and /private. Scan the volume.
Drill to ~/Library/Developer
The radial map makes Xcode's attic one obvious wedge. Click in, sort by size.
Stage, don't nuke
Queue DerivedData and dead simulators in the collector; keep Archives until the release ships.
Re-scan monthly
Five minutes after each sprint keeps the cruft from compounding.
Tools worth installing
NullDisk first — native map, staged collector, zero telemetry. Then, depending on taste:
- Delve — An honest APFS-aware treemap plus sunburst with collector cleanup.
- GrandPerspective — The tiny open-source treemap that shows your biggest files instantly.
- Diskaroo — A treemap visualizer with collector tray and smart filters.
সচরাচর প্রশ্ন
Is it safe to delete DerivedData?
Yes — Xcode regenerates it. Archives and device support files deserve a second look first.
Which tool is best for developers?
One with honest allocated-size measurement (APFS clones lie to naive tools) and a staged workflow. NullDisk's engine was built for exactly this.