Xcode 26 CompilationCache 26GB: safe Xcode storage checklist

A practical first-pass checklist for Xcode CompilationCache.noindex 26GB. The goal is to recover space without deleting the folder that proves expensive to rebuild.

Separate Xcode storage by risk bucket

Xcode storage is not one thing. DerivedData, Archives, simulator devices, simulator runtimes, DeviceSupport, and package caches have different recovery costs.

First read-only checks

Start with read-only folder sizes, then remove regenerable build data before touching archives or runtimes tied to active projects.

du -sh ~/Library/Developer/Xcode/DerivedData
du -sh ~/Library/Developer/Xcode/Archives
du -sh ~/Library/Developer/CoreSimulator

Usually safer cleanup candidates

• DerivedData after Xcode is closed
• Old unavailable simulator devices
• Regenerable package and build caches

Review before deleting

• Archives used for release symbolication
• Simulator runtimes required by current projects
• DeviceSupport folders for devices still being tested