Everything Unslow can remove

Xcode build data

Intermediate build products and indexes. Xcode recreates them on the next build, which is slower once.

~/Library/Developer/Xcode/DerivedData

Xcode device support files

Debug symbols copied from iPhones and other devices you have connected. Xcode copies them again the next time you connect that device.

~/Library/Developer/Xcode/iOS, watchOS, tvOS and visionOS DeviceSupport

SwiftUI preview data

Simulator devices Xcode creates for SwiftUI previews. They are recreated when you next open a preview.

~/Library/Developer/Xcode/UserData/Previews

Simulator caches

Cached data the iOS Simulator regenerates on demand. Your simulators and their apps are not affected.

~/Library/Developer/CoreSimulator/Caches

npm cache

Copies of packages npm has downloaded. They are fetched again the next time a project needs them.

~/.npm/_cacache

Yarn cache

Copies of packages Yarn has downloaded. They are fetched again when a project needs them.

~/Library/Caches/Yarn

Homebrew downloads

Installer archives Homebrew keeps after installing a package. Installed software is not affected.

~/Library/Caches/Homebrew

pip cache

Python packages pip has downloaded. They are fetched again when needed.

~/Library/Caches/pip

CocoaPods cache

Pod sources CocoaPods has downloaded. They are fetched again on the next `pod install`.

~/Library/Caches/CocoaPods

Gradle caches

Dependencies and build outputs Gradle has cached. The next Android build downloads what it needs again.

~/.gradle/caches

Go build cache

Compiled Go packages. The Go toolchain rebuilds them as needed.

~/Library/Caches/go-build

Chrome update copies

Copies of older Chrome versions that Chrome made to update while running, then left behind. Copies of the version you have now share its space and free nothing, so they aren’t listed. Cleared only while Chrome is closed.

Your temporary folder: X/com.google.Chrome.code_sign_clone

Swift Package Manager cache

Package sources and prebuilt binaries SwiftPM has downloaded. They are fetched again the next time a package resolves.

~/Library/Caches/org.swift.swiftpm

Cargo registry cache

Rust crates Cargo has downloaded and unpacked. They are fetched again on the next build that needs them.

~/.cargo/registry/cache and ~/.cargo/registry/src

uv cache

Python packages uv has downloaded and built. They are fetched again when a project needs them.

~/.cache/uv and ~/Library/Caches/uv

pnpm store

pnpm's shared package store. Projects keep working until their next install, which downloads what it needs again.

~/Library/pnpm/store

Bun cache

Packages Bun has downloaded. They are fetched again on the next install.

~/.bun/install/cache and ~/Library/Caches/bun

Unavailable simulators

Simulators whose iOS version is no longer installed, so Xcode can’t run them. Your working simulators are not affected.

~/Library/Developer/CoreSimulator/Devices, only simulators whose iOS version isn't installed

iPhone and iPad update files

Copies of iOS and iPadOS that Finder or Apple Configurator downloaded to update or restore a device. They’re downloaded again if you need them.

~/Library/iTunes/iPhone, iPad and iPod Software Updates, and Apple Configurator's firmware cache (.ipsw files only)

App logs

Records apps write about what they’re doing, for their developers. Apps start new ones as they run. macOS’s own logs and crash reports are left alone.

~/Library/Logs, except macOS's own logs and crash reports

App caches

Files each installed app keeps so it loads faster. They refill as you use the app, so the space comes back. Sign-ins, settings and documents aren’t touched.

Cache folders inside an installed app's folder in ~/Library/Application Support, and the app's own folder in ~/Library/Caches. Cleared only while that app is closed.

Maven repository

Java dependencies Maven has downloaded, which it fetches again on the next build. It also holds anything you installed there yourself with mvn install, which can’t be downloaded again.

~/.m2/repository

Mail attachment copies

Copies Mail saved when you opened or previewed attachments. The attachments stay in your email, but if you edited one after opening it, your changes are only in this copy.

~/Library/Containers/com.apple.mail/Data/Library/Mail Downloads

node_modules in old projects

Dependencies of projects untouched for 90 days. Running npm install brings them back if you return to a project.

node_modules folders in projects untouched for 90 days

Installers in Downloads

Disk images and installer packages. Once the app they contain is installed, these are usually no longer needed.

~/Downloads: .dmg, .pkg, .mpkg and .xip files

Xcode archives

Builds you archived for distribution. They are needed to read crash reports from those builds, so keep any you still support.

~/Library/Developer/Xcode/Archives

iPhone and iPad backups

Local backups made by Finder. Only remove one if you have a newer backup elsewhere, such as iCloud.

~/Library/Application Support/MobileSync/Backup