A disk diagnostic for macOS developers. It finds what ate the disk and where it went: Docker volumes, simulator runtimes, build caches, VM images. Before you remove any of it, Backspace tells you what will actually come back.
01 · what you get
The diagnostic is free. Always. #
Every scan, every number, every finding and the reasoning behind it costs nothing. You pay only to act on what it found and to watch the disk over time.
Free
- Full scan of projects, caches, Docker, simulators
- Every size, every finding
- The reasoning: why this is here and what it is
- What would actually come back if removed
Paid, one purchase
- Safe removal
- Background monitoring
- Alerts
- History and deltas
- Look inside volumes
- Audit log
Finding out is free. Acting on it is what costs.
02 · projects & caches
58 projects. 101.93 GB. #
Found artifact-first: Backspace walks for node_modules, target, Pods and their kin, then derives the project from the artifact. A project without git, or one whose source you already deleted, still shows up.
6.75 GB of it hasn't been touched in six months or more.
03 · docker
Ask the tools about themselves. #
OrbStack, Docker Desktop, Colima, Podman. Backspace asks each runtime where it lives instead of guessing from hardcoded paths, because every one of them is configurable and the list will never be complete.
126.2 GB here, and 212 of 246 volumes belong to no project at all.
04 · simulators
16 simulators that cannot start. #
44.92 GB across 27 simulators. Sixteen of them are stranded: the iOS runtime they need is gone, but their data stays on disk until you say otherwise.
And the numbers stay honest. A runtime's mounted volume is largely an APFS clone of a source asset it leaves behind, so Backspace refuses to claim you'll get both back.
05 · activity
Where did 10 GB go since yesterday? #
Free space sampled continuously, with the deltas attributed to what actually changed. The question stops being "my disk is full" and becomes "this filled it, at this hour".
06 · audit log
Everything it removed, on the record. #
The exact command, the exact path, where it went and whether it worked. Nothing is swept up silently, and bulk actions never touch volumes: those go one at a time, ticked by hand.
07 · after the cleanup
It keeps watching. #
A one-off sweep buys you a month. Backspace samples free space in the background, tells you the moment a build starts eating the disk again, and keeps the history so you can see which project is the repeat offender.
That is what the licence is for: never wondering where the gigabytes went again.
08 · privacy
Two requests. No analytics in the app. #
What Backspace finds on your disk stays on your disk. Paths, project names and sizes live in a local SQLite database and are never uploaded. There is no analytics SDK, no telemetry and no user identifier. The app's entire outbound surface is this (this website separately counts anonymous page views and download clicks with self-hosted Rybbit):
| Destination | When | What is sent |
|---|---|---|
| api.lemonsqueezy.com | Licence activation and checks | Your licence key, plus the computer name on first activation. |
| backspace.tedydev.com | Update check | A plain request for the appcast file. |
09 · how it measures
Allocated blocks, never apparent size. #
A sparse VM image will happily report 8 TB of apparent size on a 926 GB disk. Every number in Backspace is what the file actually occupies.
// every runtime path is user-configurable — so we ask, never assume
const runtimes = await exec("docker context ls")
const usage = await exec("docker system df -v")
// size is st_blocks * 512, not st_size
const onDisk = stat.blocks * 512
10 · pricing
One purchase, no subscription. #
$24.99 one time, plus local tax where applicable
Buy once, use it on your Macs, keep the version you bought. Updates arrive through Sparkle.