Developer files taking up space on Mac, folder by folder.

How much space developer files take

Here's one developer Mac, measured in October 2026. The node_modules figure is what du counted across every project in one code folder:

That's over 160 GB, and none of it is source code. Every row can be rebuilt or downloaded again. The question is only how long you'll wait when you need it back.

Xcode: DerivedData, CoreSimulator, and DeviceSupport

• DerivedData is build products and the index, one folder per project. Quit Xcode and move the folders inside it to the Trash; the next build is slower and indexing runs again.
• CoreSimulator holds every simulator you've created, with the apps and data installed on it. Simulator runtimes, the bigger part, are managed by macOS and count toward System Data. To remove simulators whose runtime is gone, which can't run anyway:

  xcrun simctl delete unavailable
  xcrun simctl runtime list
  xcrun simctl runtime delete <identifier>

• iOS DeviceSupport is debug symbols copied from each iPhone or iPad OS version you've plugged in, a few gigabytes each. Delete folders for versions you no longer debug on; Xcode copies them again when that device connects.

How to clear Xcode cache covers each folder, plus archives and Swift build folders.

How to delete node_modules

Each JavaScript project installs its own copy of every dependency, so a dozen projects means a dozen node_modules folders, often hundreds of megabytes each. To list yours by size:

find ~ -name node_modules -type d -prune -exec du -sh {} + 2>/dev/null | sort -h | tail -20

Or use npkill, a small tool that finds them for you. Run it from your code folder:

cd ~/code
npx npkill

It lists every node_modules below that folder with its size. Move to one with the arrow keys and press Space to delete it. npkill deletes for good rather than moving to the Trash, so stick to projects you can reinstall. Delete node_modules in projects you haven't touched in a while; npm install brings it back from the lockfile. Package manager caches are a separate folder: see npm, Yarn, and every other tool.

Docker.raw

Docker Desktop keeps every image, container, volume, and build cache inside one file, Docker.raw. It's a sparse file, so Finder can show it at hundreds of gigabytes while du shows what it really uses: on the Mac above, Finder said 926 GB and du said 29 GB.

Never move it to the Trash: that deletes every image, container, and volume at once. Reclaim space with Docker's own command, which asks first:

docker system df
docker system prune

Docker system prune, explained covers every flag, including the one that removes volumes.

More folders that grow on their own: iCloud Drive, Dropbox, and the rest of the list. For local AI models, which can outgrow all of these, see delete local AI models.