How to Clean Unreal Engine Common DerivedDataCache (DDC)
Location & Quick Verdict
%LocalAppData%\UnrealEngine\Common\DerivedDataCache
Unreal Engine 5 stores compiled shaders, texture mipmaps, and mesh distance fields in DerivedDataCache across all projects.
How Timeline Previews, Conform Audio & Render Scratch Fill Unreal Engine Common DerivedDataCache (DDC)
Non-linear video editors (NLEs), streaming encoders, 3D DCC tools, and DAWs continuously write uncompressed audio conform files (.cfa), waveform peak indexes (.pek), proxy transcodes, and frame-accurate undo scratch into %LocalAppData%\UnrealEngine\Common\DerivedDataCache. Even after you finish exporting and archiving a client project, gigabytes of intermediate timeline render caches remain permanently allocated on your scratch disk.
On 4K/8K timelines or multi-scene streaming setups, Unreal Engine Common DerivedDataCache (DDC) routinely consumes 8.0 GB – 50.0 GB of high-speed SSD space. Safely pruning stale media caches reclaims scratch bandwidth immediately; if you ever reopen an older project file, the application simply regenerates audio waveforms and timeline previews in the background.
# Inspect current disk footprint of Unreal Engine Common DerivedDataCache (DDC) (Read-Only)
$target = "$env:LOCALAPPDATA\UnrealEngine\Common\DerivedDataCache"
Get-ChildItem -Path $target -Recurse -Force -ErrorAction SilentlyContinue |
Measure-Object -Property Length -Sum |
Select-Object Count, @{Name="SizeGB";Expression={[math]::Round($_.Sum / 1GB, 2)}}
Manual Cleaning Instructions
- 1 Close Unreal Editor and Epic Games Launcher.
- 2 Press Windows Key + R, type %localappdata%\UnrealEngine\Common\DerivedDataCache and press Enter.
- 3 Select all cached subfolders and delete them.
Note: If Windows alerts that a file is in use or locked by a background process, close the associated task in Task Manager before deleting, or use SWEEPR Cleaner to release locked handles safely.
Sub-Folders & Cache Locations Breakdown for Unreal Engine Common DerivedDataCache (DDC)
Modern Windows applications and system services split their disk footprint across multiple sub-directories (`Cache_Data`, `Service Worker\CacheStorage`, `Code Cache`, `GPUCache`, and `Crashpad\reports`). Review which sub-folders inside Unreal Engine Common DerivedDataCache (DDC) are safe to purge and which files remain protected:
| Sub-Folder / Cache Location | Storage Role | Typical Footprint | Deletion Safety |
|---|---|---|---|
| %LocalAppData%\UnrealEngine\Common\DerivedDataCache | Primary Media Cache, Proxy Scratch & Render Previews | 8.0 GB – 50.0 GB | 🟢 100% Safe (Re-renders on Demand) |
| %LocalAppData%\UnrealEngine\Common\DerivedDataCache\Media Cache Files (*.cfa, *.pek) | Conformed Audio Waveforms & Timeline Peak Files | 2.0 GB – 25.0 GB | 🟢 100% Safe |
| %LocalAppData%\UnrealEngine\Common\DerivedDataCache\GPUCache & Code Cache | Hardware-Accelerated Viewport & UI Plugin Cache | 300 MB – 3.0 GB | 🟢 100% Safe |
| %LocalAppData%\UnrealEngine\Common\DerivedDataCache\logs & Crashpad\reports | Render Session Logs & Crash Dump Archives (.dmp) | 200 MB – 4.5 GB | 🟢 100% Safe |
| Project Timelines (.prproj / .drp / .blend) & LUTs | Source Footage, Edit Timelines, Presets & Exported Renders | Protected | 🔒 Protected — Never Touched |
Frequently Asked Questions
Is it safe to delete Unreal Engine Common DerivedDataCache (DDC)?
Yes, 100% safe. 100% safe to clean. Reclaims up to 50 GB from old UE4/UE5 projects without altering your project source files.
How much storage space will cleaning Unreal Engine Common DerivedDataCache (DDC) free up?
Users typically reclaim 8.0 GB – 50.0 GB on Windows 10 and Windows 11 systems depending on update frequency and active cache retention in %LocalAppData%\UnrealEngine\Common\DerivedDataCache.
Will clearing Unreal Engine Common DerivedDataCache (DDC) delete my video projects, drafts, or saved recordings?
No. Project timelines, source media clips, and exported videos are stored in your project folders—not in %LocalAppData%\UnrealEngine\Common\DerivedDataCache. If you reopen an active project after cleaning, the software automatically rebuilds any needed waveform peaks or preview frames.
Where is Unreal Engine Common DerivedDataCache (DDC) located on Windows 10 and Windows 11?
It is stored at %LocalAppData%\UnrealEngine\Common\DerivedDataCache. You can paste that path directly into the Windows Run dialog (Win + R) or File Explorer address bar to inspect it.
Manual File Explorer vs. 1-Click SWEEPR Cleanup
| Feature | Manual Deletion | SWEEPR Cleaner |
|---|---|---|
| Locked File Handling | Fails on locked processes | Safe background release |
| Accidental Deletion Risk | Moderate (easy to delete wrong folder) | Zero (strict rules & hashes) |
| Safety Undo Rollback | None (Shift+Del is permanent) | 7-Day Automatic Rollback |
| Time Required | 10–20 minutes per app | < 60 seconds across 40+ areas |
Related Windows Cleanup Guides & Hidden Space Hogs
Clean Unreal Engine Common DerivedDataCache (DDC) Automatically
SWEEPR Cleaner safely clears Unreal Engine Common DerivedDataCache (DDC) along with 40+ other hidden app folders and leftover files in one click—covering up to 5 devices (Windows, Mac, Android & iOS) with a 7-day undo safety net.