# HEIC files show no thumbnail previews

> You can open the photos individually but the folder is a wall of identical grey icons, which makes finding anything impossible. The cause is usually the thumbnail cache, not the codec.

Source: https://jpg-heic.com/fix/heic-not-showing-thumbnails | Section: Troubleshooting | Updated: 2026-08-31

## Check the obvious things first

 - **Are thumbnails switched on at all?**
 In File Explorer, open **View → Options → View** and make sure
 **Always show icons, never thumbnails** is unticked. Performance-tuning guides and some
 corporate images turn this on, which disables previews for every format, not just HEIC.

 - **Is the view mode showing icons?**
 Details and List views show file-type icons by design. Switch to **Large icons** or
 **Extra large icons** to see actual previews.

 - **Can you open a file?**
 If the photo opens in the Photos app, the codec is working and this is a cache problem —
 go to the next section. If it does not open,
 [the codec is missing](https://jpg-heic.com/fix/heic-codec-missing-windows) and thumbnails cannot work
 until that is fixed.

## Clearing the thumbnail cache on Windows

Windows caches previews in a database that regularly becomes stale or corrupted, particularly after
 installing a codec — entries generated when the format was unreadable stay cached as blanks.

 - **Run Disk Cleanup**
 Press Win+R, type `cleanmgr`, select your system drive, tick
 **Thumbnails** and click OK.

 - **Restart Explorer**
 Open Task Manager, find **Windows Explorer**, and choose **Restart**. The cache rebuilds as
 you browse folders.

 - **Give it time on large folders**
 A folder of two thousand photos takes a while to regenerate. Leave the window open and scroll
 slowly rather than assuming it has failed.

## macOS

Finder previews for HEIC are handled by QuickLook, which is built in. If they stop working:

`qlmanage -r cache` then `killall Finder`

If previews are missing only inside a particular folder, delete the `.DS_Store` file there
 — it stores per-folder view settings and occasionally corrupts.

## Linux

Install the thumbnailer alongside the library: `sudo apt install libheif-examples
 heif-gdk-pixbuf`. Then clear the cache with `rm -rf ~/.cache/thumbnails/*` and restart
 your file manager. GNOME Files, Dolphin and Thunar all use the same freedesktop thumbnail
 specification, so one thumbnailer serves all of them.

 **When nothing else works.** A persistently blank folder that resists every fix is usually a
 sign the files themselves are placeholders rather than real photos — iCloud stubs that were never
 fully downloaded, for example. Check the file sizes. If they are a few kilobytes rather than a few
 megabytes, the issue is the transfer, not the display.

## Frequently asked questions

**Why do my HEIC files show blank icons?**

Either the HEVC codec is missing, so Windows cannot generate a preview, or the thumbnail cache contains stale blank entries from before the codec was installed. Test by opening one file — if it opens, it is the cache.

**How do I clear the thumbnail cache in Windows?**

Run cleanmgr, select your system drive, tick Thumbnails and confirm. Then restart Windows Explorer from Task Manager so the cache rebuilds as you browse.

**Why do thumbnails work for some HEIC files and not others?**

Files with unusual container structures — bursts, Live Photos, some Portrait shots — can defeat the thumbnailer even when ordinary photos work. Mixed results usually point to file variety rather than a broken installation.

**Do HEIC thumbnails work on Linux?**

Yes, once heif-gdk-pixbuf and the libheif thumbnailer are installed. Clear ~/.cache/thumbnails afterwards, since blank entries generated beforehand persist.