Your Mac is storing 30 GB of Apple asset packs, and you can see them
What /System/Library/AssetsV2 is, why it held 33 GB on our Mac, which parts you can remove, and why simulator runtimes get stuck once Xcode is gone.
What is AssetsV2 on a Mac?
It is the folder where macOS keeps downloadable parts of the system: simulator runtimes for Xcode, Siri and dictation models, dictionaries, and the models behind features like Photos editing. Each subfolder is named com_apple_MobileAsset_ followed by what it holds, so the name tells you which feature downloaded it.
How do I see what is in AssetsV2?
Run this in Terminal. It lists the twelve largest entries with their sizes, and changes nothing:
du -sk /System/Library/AssetsV2/* 2>/dev/null \
| sort -n | tail -12 | awk '{printf "%5d MB\t%s\n", $1/1024, $2}'On our test Mac the largest were:
| Asset | Size | What it is |
|---|---|---|
iOSSimulatorRuntime | 24.9 GB | iPhone and iPad simulators downloaded for Xcode |
UAF_Siri_Understanding | 2.4 GB | On device Siri language models |
LinguisticData and UAF_LinguisticData | 2.2 GB | Text analysis data per language |
UAF_Photos_SpatialPhotosRelive | 0.9 GB | On device model for Photos |
UAF_Photos_MagicCleanup | 0.8 GB | On device model for Photos editing |
UAF_Speech_AutomaticSpeechRecognition | 0.4 GB | Offline dictation models |
Does AssetsV2 count against my disk space?
Yes. The path starts with /System, but the folder lives on the Data volume, the same one as your files, so every gigabyte in it is a gigabyte you cannot use. The storage screen files it under System Data with no breakdown, which is the limit of that screen, and why System Data looks so large.
Can I delete AssetsV2 on a Mac?
Not by hand. The folder carries the restricted flag, so System Integrity Protection, which is on by default, refuses changes to it. Each part can only be removed by the feature that downloaded it: simulators through Xcode's tools, language assets through System Settings.
Is it safe to delete AssetsV2?
Removing parts the supported way is safe. Forcing it is not worth it: macOS downloads again what a feature needs, so the space comes back, and turning off System Integrity Protection to get round the flag weakens the Mac's protection for a temporary gain. Leave the Siri, language and Photos models alone unless you remove the language or feature they belong to; Siri and speech assets covers those.
How do I remove simulator runtimes?
With Xcode installed, list them and delete the ones you no longer test on:
xcrun simctl runtime list
xcrun simctl runtime delete <build or identifier>
xcrun simctl delete unavailableThe simulated devices and their data are a separate folder from these runtime images: simulator devices explains that one.
Why can I not delete simulator runtimes after removing Xcode?
Because the tool that deletes them goes with Xcode. On our test Mac, which has the Command Line Tools but not Xcode, xcrun simctl answered "unable to find utility", and the 24.9 GB of runtimes stayed with no supported way to remove them. Installing Xcode again brings the tool back; check how much space Xcode needs first, because on a nearly full disk that can be the hard part. The Command Line Tools alone do not include it: see what the Command Line Tools are.
The process that downloads these is mobileassetd; feature rollouts are kept separately in the Trial folder.
Common questions
What is /System/Library/AssetsV2 on a Mac?
It is where macOS stores downloadable system assets: simulator runtimes, Siri language models, speech recognition data, dictionaries and on device machine learning models. On our test Mac it held 33 GB in October 2026.
Does AssetsV2 count against my disk space?
Yes. Although the path begins with /System, the folder is on the Data volume, so its contents fill your drive. The storage screen counts it under System Data with no breakdown.
Can I delete Apple asset packs to free space?
Only through the tool that owns them. Simulator runtimes go with xcrun simctl runtime delete while Xcode is installed, and language assets shrink when you remove a language in System Settings. The folder is protected, so deleting by hand is refused.
Why are simulator runtimes still on my Mac after I deleted Xcode?
The command that removes them comes with Xcode. Without it, xcrun simctl is not available, so the runtimes stay. Install Xcode again to remove them, and delete them first next time.