Everything Cachet looks for

Cachet only looks in locations it knows. This list is made from the same rules the app uses, so it is always exactly what Cachet checks.

An item is only listed when it uses at least 1 MB. Each one starts at the confidence shown here; what Cachet finds on your Mac can lower it, never raise it (see What do High, Medium and Review mean?).

Developer

Xcode build data and device support.

• DerivedData (Xcode): Build products and indexes Xcode creates while you work. Nothing you wrote lives here. If removed: Xcode rebuilds it the next time you build each project, which takes a few minutes. Starting confidence: High.
• iOS DeviceSupport (Xcode): Debug symbols Xcode copied from iPhones and iPads you’ve connected. If removed: Xcode copies them again the next time you connect that device, which can take several minutes. Starting confidence: High.
• watchOS DeviceSupport (Xcode): Debug symbols Xcode copied from Apple Watches you’ve connected. If removed: Xcode copies them again the next time you debug on that watch. Starting confidence: High.
• Previews (Xcode): Simulators and build data Xcode uses to show SwiftUI previews. If removed: Xcode recreates it the next time a preview runs; the first preview is slower. Starting confidence: Medium.
• Simulator caches (Xcode): Temporary files the iOS Simulator keeps to start faster. If removed: The Simulator rebuilds them the next time it starts. Starting confidence: High.
• Archives (Xcode): Builds you archived for release or TestFlight, with their debug symbols. If removed: Gone for good once you empty the Trash. Keep any you may need to read crash reports. Starting confidence: Review.

Package caches

Downloaded packages for npm, Swift, Homebrew and others.

• npm cache (npm): Copies of every package npm has downloaded, kept so installs run faster. Your projects don’t use these files directly. If removed: npm downloads packages again as you need them, so the next install is slower. Starting confidence: High.
• Yarn cache (Yarn): Packages Yarn has downloaded, kept so installs run faster. If removed: Yarn downloads them again as projects need them. Starting confidence: High.
• pip cache (pip): Python packages pip has downloaded or built. If removed: pip downloads or builds them again when you next install them. Starting confidence: High.
• Homebrew downloads (Homebrew): Installers Homebrew downloaded. The tools you installed live elsewhere. If removed: Homebrew downloads them again only if you reinstall something. Starting confidence: High.
• Swift packages (Swift Package Manager): Copies of Swift packages your projects depend on, shared between projects. If removed: Xcode or swift fetches them again the next time a project resolves its packages. Starting confidence: High.
• CocoaPods cache (CocoaPods): Pods CocoaPods has downloaded, kept so installs run faster. If removed: CocoaPods downloads them again on the next pod install. Starting confidence: High.
• Go build cache (Go): Compiled results Go keeps to make builds faster. If removed: Go rebuilds what it needs; the next build is slower. Starting confidence: High.
• Playwright browsers (Playwright): Browser builds Playwright downloaded for automated tests. If removed: Playwright downloads the browsers again on the next test run, which can take a few minutes. Starting confidence: Medium.
• Playwright browsers (MCP) (Playwright): Browser builds downloaded for Playwright’s MCP server. If removed: They download again the next time the server starts a browser. Starting confidence: Medium.
• Gradle caches (Gradle): Dependencies and build outputs Gradle keeps between builds. If removed: Gradle downloads and rebuilds them; the next build is much slower. Starting confidence: Medium.

App caches

Temporary files apps rebuild as you use them.

• Google Chrome cache (Google Chrome): Web pages and images Chrome keeps so sites load faster. Bookmarks, passwords and history aren’t stored here. If removed: Chrome downloads what it needs again as you browse. Starting confidence: High.
• Spotify cache (Spotify): Music and artwork Spotify keeps so it can play and load faster. If removed: Spotify fetches it again as you listen. Starting confidence: High.
• Each folder inside (the app): Temporary files {name} keeps so it can load faster. If removed: The app rebuilds what it needs as you use it. Starting confidence: Medium.

Old installers

Installers in Downloads that haven’t changed in 90 days.

• Each installer file (Downloads): An installer you downloaded that hasn’t changed in over 90 days. If removed: Gone once you empty the Trash. Most installers can be downloaded again from their website. Starting confidence: Review.

Logs

Log files apps write while they run.

• Each folder inside (the app): Log files {name} writes while it runs, mostly useful for troubleshooting. If removed: The app starts fresh logs. Only the history of past problems is lost. Starting confidence: Medium.

Simulators

One Terminal command removes devices that can’t run any more.

• Simulator devices (Xcode): Every iPhone, iPad and Watch simulator Xcode has created. If removed: Removed with Xcode’s own command, so only devices that can’t run any more go. Starting confidence: Review.