Why Is Nemo Not Showing Thumbnails on Linux Mint?
The Nemo file manager is the default file browser on Linux Mint Cinnamon. When image previews, video thumbnails, or PDF thumbnails stop appearing — replaced by generic file icons — the cause is almost always one of four things: thumbnail generation is disabled in Nemo preferences, the file size limit is set too low, a required thumbnailer package is missing, or the thumbnail cache has become corrupt.
This guide covers every fix in order from quickest to most thorough, so you can restore thumbnail previews without reinstalling Nemo or losing your files.
Fix 1: Enable Thumbnails in Nemo Preferences
The most common cause: thumbnails have been accidentally disabled in Nemo settings.
- Open Nemo (Files).
- Click Edit in the menu bar → Preferences.
- Go to the Display tab.
- Find Show thumbnails and set it to Always (not "Local Files Only" or "Never").
- Also check the Only for files smaller than setting — increase it to 100 MB or higher if you have large image/video files.
- Click Close and wait a few seconds for thumbnails to regenerate.
Fix 2: Increase the File Size Limit for Thumbnails
By default, Nemo skips thumbnails for files above a certain size. If your images or videos are large (raw camera files, 4K video), they may exceed the limit:
- In Nemo → Edit → Preferences → Display.
- Set Only for files smaller than to a much higher value — try 500 MB for video files.
Alternatively, set it via dconf-editor:
sudo apt install dconf-editor
Open dconf-editor, navigate to org → nemo → preferences, and set thumbnail-limit to your preferred maximum size in bytes.
Fix 3: Install Missing Thumbnailer Packages
Nemo relies on external thumbnailer packages to generate previews for different file types. If these aren't installed, Nemo can't create thumbnails for those formats:
For video thumbnails (MP4, MKV, AVI):
sudo apt install ffmpegthumbnailer tumbler
For document thumbnails (PDF, LibreOffice):
sudo apt install tumbler-plugins-extra
For raw image thumbnails (RAW, CR2, NEF):
sudo apt install tumbler libgdk-pixbuf2.0-dev
For audio file thumbnails (MP3 album art):
sudo apt install xplayer-thumbnailer
After installing, restart Nemo:
nemo -q && nemo &
Fix 4: Clear the Thumbnail Cache
A corrupt or outdated thumbnail cache is a frequent cause of missing or broken thumbnails. Clearing it forces Nemo to regenerate everything:
rm -rf ~/.cache/thumbnails
rm -rf ~/.thumbnails
Then restart Nemo:
nemo -q
Open Nemo again and navigate to a folder with images — thumbnails will regenerate from scratch. Large folders may take a minute to populate.
Fix 5: Switch View Mode and Toggle Zoom Level
Sometimes thumbnails won't appear in icon view but will after a zoom level change or view mode toggle:
- In Nemo, press Ctrl + 1 to switch to icon view (if not already).
- Use Ctrl + + to zoom in or Ctrl + - to zoom out — this can force Nemo to request thumbnails at the new size.
- Also try clicking View → Show Thumbnails to toggle it on.
Fix 6: Fix Thumbnail Permissions on External Drives
Thumbnails often won't generate for files on external USB drives or NTFS-formatted drives because the cache write location lacks correct permissions. Check:
ls -la ~/.cache/thumbnails/
The folder should be owned by your user. If not, fix it:
chown -R $USER:$USER ~/.cache/thumbnails
chmod 700 ~/.cache/thumbnails
For NTFS drives, thumbnails may not persist between sessions. Nemo needs a Linux-writable cache location, and it can't write persistent thumbnails back to NTFS metadata the same way.
Fix 7: Restart the Thumbnailing Service
The tumbler daemon handles thumbnail generation in the background. If it's crashed, thumbnails won't generate even with correct settings:
pkill tumblerd
tumblerd &
Or kill all Nemo-related processes and restart:
nemo -q
pkill tumblerd
nemo &
Fix 8: Rebuild the Thumbnail Cache with gnome-thumbnail-factory
For a deeper cache rebuild, use the nautilus thumbnail tool (compatible with Nemo since they share the same thumbnail backend):
sudo apt install nautilus
nautilus -q
Then clear and regenerate:
rm -rf ~/.cache/thumbnails/*
nemo -q && nemo
Navigate to your photo or video folder and thumbnails will regenerate.
Still No Thumbnails in Nemo?
If thumbnails still aren't appearing after all these fixes, the issue may be a Nemo version bug introduced in a recent Linux Mint update, a conflict with a file manager extension, or a permissions problem specific to your home folder setup. CloudHouse Technologies offers pay-per-ticket remote Linux support — a specialist can connect to your system, diagnose the exact thumbnailer failure, and fix it in one session.
Frequently Asked Questions
Why does Nemo show thumbnails for images but not for videos on Linux Mint?
Video thumbnails require the ffmpegthumbnailer package. Install it with: sudo apt install ffmpegthumbnailer tumbler, then restart Nemo. Without this package, Nemo has no way to extract a frame from video files for the preview.
How do I make Nemo show thumbnails for files on an external hard drive?
In Nemo preferences, set "Show thumbnails" to "Always" (not "Local Files Only"). Also ensure the external drive is mounted with write permissions so Nemo can cache thumbnails. NTFS drives may have persistent issues — reformatting to ext4 resolves them completely.
Where are Nemo thumbnails stored on Linux Mint?
Thumbnails are cached at ~/.cache/thumbnails/ — divided into "normal" (128×128px) and "large" (256×256px) subfolders. Nemo reads from this cache for fast display. Clear the folder to force regeneration if thumbnails are outdated or broken.
Can I make Nemo generate thumbnails for RAW camera files?
Yes — install the RAW image thumbnailer support: sudo apt install tumbler libgdk-pixbuf2.0-dev. For better RAW support, also install ufraw-batch: sudo apt install ufraw-batch. Then clear the thumbnail cache and reopen Nemo.
Why did Nemo thumbnails stop working after a Linux Mint update?
A Nemo version update can reset thumbnail settings or change how thumbnailer packages are called. After any Nemo update, check that ffmpegthumbnailer and tumbler are still installed (sudo apt install ffmpegthumbnailer tumbler), clear the thumbnail cache (rm -rf ~/.cache/thumbnails), and verify preferences in Edit → Preferences → Display.