Exact accounting
The reclaimable number is the space you will actually get back.
naive sum84.4 GB
device bytes33.9 GB
Native macOS utility
Make room for the next build.
WD-40 finds and removes development build artifacts from the menu bar. Nothing is selected until you choose it.
Scanning
Targets appear first. Measuring sizes…
rust targetsmeasuring
✓project-alphatarget · recentrecent
project-betatarget…
node modulesmeasuring
web-clientnode_modules…
RescanSettings
Cleaning33.9 GB
removing
project-alpha/target
project-alpha/target
✓project-betaremoved
project-alphacurrent
·web-clientwaiting
33.9 GBfreed
✓Rust targets removeddone
—Skipped — recentkept
It counts what the disk holds.
Logical file sizes can count the same APFS data more than once. WD-40 reads device bytes from the extent map.
Nothing armed
Recent builds stay excluded until you tick them. The button names what it will remove.
Toolchains leave safely
Anything still used by a default, override, pin, or link is never offered.
$ rustup toolchain uninstall
✓ unused toolchain removed
✓ unused toolchain removed
Names now.
Sizes behind them.
The two-phase scan puts targets on screen immediately, then fills in exact sizes as the extent map is measured.
A deliberate clean
Stop after the current target.
The cleaning view names what is coming off. Removals are permanent and removed directories rebuild with the next build.
Build artifactsmeasuring
Rust targetsrecent excludedready
Node modulesverified by heuristicready
Build outputproject manifest foundready
Built for build residue.
WD-40 looks for known artifacts and verifies ambiguous directories against their contents or neighboring project files.
Rust targetstarget directories, temporary cc-target build directories, and cargo-target build directories
Packages & outputnode_modules, .next, dist, and build
CachesDerivedData, ModuleCache, simulator caches, and package-manager download stores
Rust toolchainsToolchains that nothing points at any more
The same rules from the terminal.
The app and CLI share one config file at ~/.config/wd-40/config.toml.
$ wd40 scan
$ wd40 clean --dry-run
$ wd40 scan -g rust
$ wd40 clean-old -d 14
$ wd40 clean --dry-run
$ wd40 scan -g rust
$ wd40 clean-old -d 14
Source install
Put WD-40 in the menu bar.
The first release binary is not published yet. Build the app or CLI from the MIT-licensed source.
$ git clone https://github.com/sunoj/wd-40 && cd wd-40
$ make install # menu bar app → /Applications
$ make cli # CLI → ~/.cargo/bin/wd40
Get WD-40 on GitHub$ make install # menu bar app → /Applications
$ make cli # CLI → ~/.cargo/bin/wd40
Details
What does WD-40 remove?
Development build artifacts: Rust targets, Node modules, build output, caches, and unused Rust toolchains. Detection uses heuristics rather than directory names alone.
What happens to recent builds?
They are excluded until you explicitly select them. Nothing is selected by default.
Does removal use the Trash?
No. Removals are permanent. Removed directories are recreated by the next build that needs them.
What does it run on?
macOS 13 or later on Apple Silicon and Intel. It is one native Rust and AppKit binary, with no Electron or web view.