MOBI and AZW3 Kindle book thumbnails in Windows Explorer

Kindle-format books (.mobi, .azw, .azw3, .prc) can show their covers in File Explorer. SageThumbs 2K reads the cover image inside each book and uses it as the thumbnail.

What you see

The MOBI format is parsed by SageThumbs' own code, so no Kindle app or extra library is needed.
The cover shows as the Explorer thumbnail, in the preview pane, and in Quick preview when you press Space.

Limits

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

EPUB books and comics get the same treatment: see EPUB covers and CBZ and CBR comic covers.

Extensions this covers

.mobi .azw .azw3 .prc

See every format SageThumbs 2K supports or browse all format guides.

Get SageThumbs 2K

Install it with winget:

winget install LunarWerxs.SageThumbs2K

Or download the installer from GitHub and run it.

Download the installer

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 doctor in a terminal. It only reads, checks the whole chain, and prints a fix under anything that is wrong.