Xcode's iOS DeviceSupport is 40 GB — which versions to keep

Last updated: October 2026

Safe to delete

Yes. Every folder in iOS DeviceSupport is a copy of symbols that still live on an iPhone or iPad. Xcode copies them again the next time a device running that iOS version is plugged in.

It costs you one wait for "Copying shared cache symbols" — a few minutes over USB, longer over Wi-Fi — and it needs the physical device. Keep the newest two versions, delete everything older, and you lose nothing you can reach.

Shodhana's Developer Tools category listing two iOS DeviceSupport versions — 17.5 (21F79) arm64e at 4.42 GB, last touched six months ago, and 16.7.8 (20H343) arm64e at 3.91 GB, a year old — beside Xcode DerivedData, Docker's buildx build cache, Cargo and npm caches, each with a last-used date. — Two DeviceSupport versions, each a row of its own, dated by when Xcode last touched it. The two newest versions on this Mac are not in the list at all: they are kept, so the only rows are the ones that can go.

What is actually in there

Your Mac runs macOS. The UIKit your app calls into at runtime lives on the phone, inside iOS's shared cache of system frameworks. When the debugger stops in viewDidLoad and you step into super, Xcode has to show you frame names for code that is not on your Mac at all. So the first time a device connects, Xcode copies the symbols for that device's exact iOS build across the cable and stores them here:

~/Library/Developer/Xcode/iOS DeviceSupport/
  17.5 (21F79) arm64e/
    Symbols/
  18.0 (22A3354) arm64e/
    Symbols/
  18.6 (22G86) arm64e/
    Symbols/

One folder per iOS version, per build number, per architecture. The Symbols directory inside each is the entire system framework set of that iOS release, with names attached — which is why one folder is a few gigabytes, and recent releases are commonly three to six.

The same thing happens for a watch and an Apple TV, in sibling folders called watchOS DeviceSupport and tvOS DeviceSupport. They are smaller and they grow the same way.

Why it grows to 40 GB without you noticing

Three things compound. iOS ships a point release roughly every month, and each one is a new build number, so each one is a new folder. Every device you have ever attached contributes its own version — your phone, the test iPad, the colleague's phone you debugged on once at a hackathon. And Xcode never deletes any of it. There is no setting for this folder: Xcode › Settings › Components manages simulator runtimes, not device symbols. The filesystem is the only interface.

A developer who has updated one iPhone on schedule for two years has twenty-odd folders here. Only the newest one is ever used.

Which versions to keep

Keep the newest version per OS family: that is the device in your pocket. Keep one more as a spare, for the second device or the older test unit that has not updated. Delete everything else. Two per family is also what Shodhana keeps, and the rule is deliberately dumb — if an old device shows up next month, its symbols re-copy in a few minutes, so the cost of being wrong is a coffee break, not a lost build.

See what you have, biggest last, with the date Xcode last touched each one:

du -sh ~/Library/Developer/Xcode/*DeviceSupport/*/ 2>/dev/null | sort -h

ls -lt ~/Library/Developer/Xcode/iOS\ DeviceSupport/

The date is the one that matters, not the version string. A folder modified last week belongs to a device you are still using, whatever its number says. One untouched since last spring belongs to an iOS that nothing you own runs any more.

Delete safely

Quit Xcode first — not because it will break, but because deleting a folder mid-copy leaves a half-written symbol set that confuses the next debug session. Then send every version except the two newest to the Trash:

cd ~/Library/Developer/Xcode/iOS\ DeviceSupport && \
  ls -td -- */ | tail -n +3 | while IFS= read -r v; do
    mv "${v%/}" ~/.Trash/"$(date +%F) ${v%/}"
  done

ls -td sorts the folders newest first, tail -n +3 skips the two you keep, and the date prefix means a second run of this next year does not collide with the first. Repeat with watchOS DeviceSupport and tvOS DeviceSupport if you have them. Everything is recoverable until you empty the Trash.

Do not delete: the DeviceSupport inside Xcode.app

Do not touch

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport

Same name, different thing. This copy ships inside Xcode, it is part of Xcode's code signature, and removing anything from it makes the whole app fail its integrity check — Xcode either refuses to launch or macOS reports it as damaged. Reinstalling Xcode is the only fix. The folder you can clean lives in your home directory; the one you cannot lives in the app bundle.

The neighbour: XCTestDevices

One directory up, ~/Library/Developer/XCTestDevices holds simulator clones that Xcode creates for parallel test runs. They are disposable — every test run makes fresh ones — but Xcode does not always clean up after a run that was cancelled. Safe to delete when nothing is testing. If xcodebuild or the Simulator is running, wait: a test in flight is using them.