Blog
What actually fills a Mac, and how to get the space back.
CoreSimulator is taking 40 GB: the devices folder, and the simctl flags that clean runtimes~/Library/Developer/CoreSimulator/Devices grows with every simulator you ever booted, and devices outlive their runtimes. Measured on one Mac: 40 GB of devices, 33 of them orphaned, 34 GB of runtime images. The commands that clear each part, with a dry run first.CleanMyMac alternative for developers: one price, no subscription, and it shows you the pathsCleanMyMac charges yearly and hides what it deletes behind a big Clean button. Decruft is $19 once, scans for free, and lists every path before anything moves. What each one does, and when CleanMyMac is still the right pick.DaisyDisk shows you the disk. It will not tell you what is safe to deleteDaisyDisk's map is the best way to see where space went. Its lowest reviews all say the same thing: it found the 200 GB of System Data and could not say what any of it was. That is the question Decruft answers.How to delete old iOS simulators and runtimes on a MacSimulator runtimes are 6 to 10 GB each and Xcode never removes the old ones. Where they live since Xcode 15, the simctl commands that remove them, and what to keep.DevCleaner vs Decruft: when the free Xcode cleaner is enough, and when it is notDevCleaner is free, open source, and cleans Xcode's six folders well. It stops at Xcode. If the rest of your disk is Docker, simulators, npm and old iPhone backups, that is where Decruft picks up.Docker.raw is 60 GB and empty. Why the file never shrinks on a Mac, and how to reclaim itDocker Desktop keeps every image and container in one sparse file that grows and never shrinks on its own. What docker system prune actually frees, and the one setting that gives the disk back.How to free up disk space on a developer's Mac: the ten folders, in order of sizeThe checklist for a Mac used for iOS, web or backend work. Each folder that fills up, where it is, what it costs to clear, and the command. Worked through on one real machine: 192 GB back.iPhone backups are taking up space on your Mac. Where they are, and which ones you can deleteEvery device you ever backed up to this Mac is still here in full. Where macOS keeps them, how to see which device each folder belongs to, and the one case where deleting loses data for good.Is it safe to delete ~/Library/Caches on a Mac? Mostly, and here is the list of what is not a cacheCaches regenerate. Some folders under ~/Library are called caches and are not. The rule for telling them apart, the folders that cost you data if you empty them, and how to clear the rest.Deleted 40 GB and the Mac still says the disk is full. Here is what is holding itThe Trash, Time Machine local snapshots and purgeable space each keep deleted files on disk for a while. How to see which one has your 40 GB, and how to release it now instead of tomorrow.Package manager caches on a Mac: npm, pnpm, yarn, pip, Gradle, Cargo, CocoaPods, and the commands that clear themEvery package manager keeps every version it ever downloaded, forever, in a hidden folder. Where each one is on macOS, how big it gets, and the one command per tool that clears it safely.Xcode is taking up 100 GB. Here is where it is, and what you can deleteXcode itself is 12 GB. The other 90 are DerivedData, old simulator runtimes, device support symbols and archives. Each folder, what recreates it, and the command to clear it.What is System Data on a Mac, and how to clear itStorage settings shows one grey bar labelled System Data and no explanation. What is inside it, folder by folder, which parts are safe to remove, which will cost you data, and the commands that clear the safe ones.