How to Clean Unreal Engine 5 Niagara VFX Simulation Cache
Location & Quick Verdict
%LocalAppData%\UnrealEngine\Common\DerivedDataCache\Niagara
Unreal Engine caches compiled GPU and CPU Niagara particle simulation scripts, vector fields, and emitter bytecode across projects.
How Timeline Previews, Conform Audio & Render Scratch Fill Unreal Engine 5 Niagara VFX Simulation Cache
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\Niagara. 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 5 Niagara VFX Simulation Cache routinely consumes 3.5 GB – 22.0 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 5 Niagara VFX Simulation Cache (Read-Only)
$target = "$env:LOCALAPPDATA\UnrealEngine\Common\DerivedDataCache\Niagara"
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 Open %localappdata%\UnrealEngine\Common\DerivedDataCache in File Explorer.
- 3 Delete stale Niagara and shader cache directories.
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 5 Niagara VFX Simulation Cache
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 5 Niagara VFX Simulation Cache are safe to purge and which files remain protected:
| Sub-Folder / Cache Location | Storage Role | Typical Footprint | Deletion Safety |
|---|---|---|---|
| %LocalAppData%\UnrealEngine\Common\DerivedDataCache\Niagara | Primary Media Cache, Proxy Scratch & Render Previews | 3.5 GB – 22.0 GB | 🟢 100% Safe (Re-renders on Demand) |
| %LocalAppData%\UnrealEngine\Common\DerivedDataCache\Niagara\Media Cache Files (*.cfa, *.pek) | Conformed Audio Waveforms & Timeline Peak Files | 2.0 GB – 25.0 GB | 🟢 100% Safe |
| %LocalAppData%\UnrealEngine\Common\DerivedDataCache\Niagara\GPUCache & Code Cache | Hardware-Accelerated Viewport & UI Plugin Cache | 300 MB – 3.0 GB | 🟢 100% Safe |
| %LocalAppData%\UnrealEngine\Common\DerivedDataCache\Niagara\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 5 Niagara VFX Simulation Cache?
Yes, 100% safe. Safely frees gigabytes of SSD space. Niagara automatically recompiles active particle emitters when you open your level.
How much storage space will cleaning Unreal Engine 5 Niagara VFX Simulation Cache free up?
Users typically reclaim 3.5 GB – 22.0 GB on Windows 10 and Windows 11 systems depending on update frequency and active cache retention in %LocalAppData%\UnrealEngine\Common\DerivedDataCache\Niagara.
Will clearing Unreal Engine 5 Niagara VFX Simulation Cache 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\Niagara. If you reopen an active project after cleaning, the software automatically rebuilds any needed waveform peaks or preview frames.
Where is Unreal Engine 5 Niagara VFX Simulation Cache located on Windows 10 and Windows 11?
It is stored at %LocalAppData%\UnrealEngine\Common\DerivedDataCache\Niagara. 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 5 Niagara VFX Simulation Cache Automatically
SWEEPR Cleaner safely clears Unreal Engine 5 Niagara VFX Simulation Cache 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.