Thumbnails

[shipgimp]

I'm really missing the thumbnails for my pdfs.
They were fine a week or so ago then after an update they're just the yellow and black icon.
Am I missing something?
Thanks

[GitHubRulesOK]

thumbnails are an install option and can hiccup when windows prevhost is occupied on something else

• Best to back up settings (they should not be deleted but best to be safe)
• clean uinstall and re-install with the preview option selected

[Nozokyo]

I use the Portable version, which starts instantly, with no install options.

I this stored somewhere in the settings.txt file?
Or do I need to use the install version?

[GitHubRulesOK]

@Nozokyo
Thumbnails and text searching are WINDOWS functions thus any dlls Microsoft, Adobe or SumatraPDF need to be installed for windows to USE them.

[rudolphos]

I have no other PDF software installed. But I have reinstalled SumatraPDF many times with both options checked, unchecked, etc. No thumbnails are showing. The only options is to use powertoys pdf thumbnail generator (Powertoys.pdfthumnailprovider) - which is slow to the point it actually shows spinning circle cursor when pdf thumbnails are generating. This happens on Win11 25h2.

[kjk]

which version of SumatraPDF?
where do you expect them to show up? explorer?

[rudolphos]

@kjk
Sumatra 3.6.17242 pre-release 64bit. I expect them to show up in the regular file explorer and Everything search tool. I've tried many things:

• disabled powertoys pdf thumbnailer; tried with powertoys uninstalled entirely;
• reinstalled for all users, for one user;
• reinstalled with both lower options checked and with one lower checked;
• cleaned the entire thumbnail cache after every action;
• used BulkCrapUninstaller to remove SumatraPDF and leftovers with rebooting;
• tried regsvr32 "C:\Program Files\SumatraPDF\PdfPreview.dll" with some additional other cmds
• unblocked several PDFs from the web to see if that makes a difference;
• added sumatrapdf.exe and all dll files into antivirus/defender exclusions list + added .pdf files in exclusion list;
• HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\Explorer - added DWORD (32-bit) Value AllowCloudThumbnails: 1 and DisableThumbnailsOnNetworkFolders: 0; restarted
• from shellexview, opened regedit CLSID settings:

...but nothing has worked so far. Powertoys thumbnailer for some reason is the only one that is 100% reliable and works as soon as it's toggled on.

[pitter7488258450-cmyk]

I’ve been tweaking my Sumatra settings for this same reason—the default white is definitely too bright for long reading sessions.
Changing the BackgroundColor in the Advanced Options (the 'FixedPageUI' section) usually does the trick for PDFs. If you're looking for good hex codes for subtle, eye-friendly shades that aren't just pure black or white, I've used Solid Color Wallpapers to find a few solid 'paper' and 'sepia' tones that look great behind text.
Definitely try a soft grey or off-white if you want to keep it readable but save your eyes some strain!

[GitHubRulesOK]

@pitter7488258450-cmyk
This thread is about preview thumbnails not theming but theming is easy in pre-release you dont need to fiddle unless adjusting the many built in ones

[filchef]

Future request - for different file extensions - different colors for Thumbnails

[GitHubRulesOK]

@filchef it is not always that simple since when you select a file type to be assigned to a DEFAULT app it is Windows uses the app icon (ONLY one style) it can be different for smallest icons without any change to the system just the icon size as details see below where Windows uses in my case the green registered epub icon.