WebM video thumbnails in Windows Explorer
SageThumbs 2K gives WebM videos a real frame as their thumbnail in File Explorer. It decodes VP9 Profile 2 and 3, the 10-bit and 12-bit HDR kind, itself, because Windows declines those even with its VP9 extension.
What you see
- The frame comes from 30% into the video by default, adjustable in Settings ▸ Appearance.
- Only the keyframe nearest that point is read, found through the file's own index, so large files stay quick.
- HDR VP9 is decoded in pure Rust in a separate, short-lived process, so a bad file cannot take Explorer down.
Limits
- AV1 video needs Microsoft's AV1 add-on from the Microsoft Store;
st2k doctornames the one to install. - In OneDrive and other synced folders, files stored on the PC get thumbnails as anywhere else. Online-only files are left to the cloud app, since nothing is downloaded just to draw a thumbnail.
More you can do
- Press Space to play the video in Quick preview. Playback uses Windows' own codecs, and the title bar says when one is missing.
Extensions this covers
.webm
See every format SageThumbs 2K supports or browse all format guides.
Get SageThumbs 2K
Install it with winget:
winget install LunarWerxs.SageThumbs2KOr download the installer from GitHub and run it.
Windows 11 and 10, 64-bit, on x64 and Arm. The same page has a portable zip that needs no installing.
Free for personal use
Home, hobby and other non-commercial use is free: every format and every tool. A company, a shop or anyone doing paid work needs a business licence for each PC.
A business licence is US$49 per PC once, with 12 months of updates, or US$2.99 per PC a month. See business licence pricing
Thumbnails not showing?
- Windows caches thumbnails, and a file it failed on once stays failed. In SageThumbs, Settings ▸ Advanced ▸ Rebuild thumbnail cache clears the cache and restarts Explorer.
- Make sure File Explorer's "Always show icons, never thumbnails" option is off, and that the format is ticked in SageThumbs Settings ▸ File types.
- Run
st2k doctorin a terminal. It only reads, checks the whole chain, and prints a fix under anything that is wrong.