Cannot change the site logo thumbnail

Brass Contributor

I have several new sites where I cannot change the site logo thumbnail from the default image. I can change the 'site logo' but not the 'site logo thumbnail'. 
I have tried in different browsers, in private browsing, non private browsing but no matter what - when I go back in it has switched back to the default image. This seems to be a problem with new sites, older sites seem to be ok. 
This is quite annoying as the thumbnail displays in a number of places throughout SP....on the SP landing page and throughout the site/library settings.
Any help would be gratefully recieved. Thanks. 

6 Replies
I have also been experiencing the same issue with Site logo thumbnails. I have been able to successfully change the site icon from the Settings>Change the look>Header>Display menu, but changes to the site logo thumbnail do not stay after saving.
I found using jpgs rather than my usual pngs worked

@Victoria Symons 

Hi, I have been fiddling around with this issue for some time now and I don't seem to have a fix that permanently works.
What I do have is some fixes you can try, but might not always work, or only work partly. They are combined into this instruction

  1. Get the picture you want to use for a thumbnail, and name it "__siteIcon__" (double underscores in front and at the end). Just that name and nothing behind or in front of it. 
  2. Make the picture a JPG format, this seems to be working the best for me. Also try to make it small in size, I have mine at 256x256.
  3. On your SharePoint Homepage go to Settings > Site Contents > Site Assets. There you can delete all the old images you used for the thumbnail (I believe all files with __siteIcon__ in front of it).
  4. Drag and drop/upload the local JPG file you just created to this library. Quickly after select the file, and check it out (for me the three dots in upper right corner)
  5. After this refresh the browsers cashe (Crtl + F5). It might take some time for the thumbnail to update across all sites. 

I hope this helps you!



Hi Lucas and Victoria,

I have indeed found some success with using JPG images instead of PNG, which is a shame as I was hoping to include a transparent background around our Logo, but will have to settle for a plain white background in a JPG.

I have however discovered that there are discrepancies with how this works between site types. The workaround seems to work for Team Sites connected to a 365 group, but not for team sites without a 365 group, and communication sites seem to have no problem at all.

I am still not sure of the reason for the discrepancy, but it is quite frustrating.

Hi Lucas.
Thanks for your info. This is so annoying and somewhat intermittent. It's happening again on new sites today. 
I have managed to get the logo thumbnail to stick today by going to Site assets, deleting the existing "__siteIcon__.jpg " and then quickly uploading a new logo with the same file name and extension in Change the look > Header > Change site logo thumbnail. 
Bit of a phaff but it's sticking so far! Pngs are working for the site logo.
Best wishes, Vicki

@Victoria Symons This totally worked for me! Thank you!