Web Viewer Cache

I have an issue where I delete an instance from a study in the Explorer, and if I then use the Orthanc web viewer to view that study, that instance I just deleted is still viewable. Is this a bug? Should the image be removed from the Orthance Web Viewer cache upon deleting the instance from the study? If this a configuration issue, please let me know. Thank you.


For the time being, the cache of the Web viewer is not invalidated once instances/series get deleted.

If this is a problem to you, please report it on our issue tracker:

The job would consist in extending the “OnChangeCallback()” function:


Hello, I found myself running into a similar problem, has a workaround for this been implemented yet?
When I try to delete the contents of the “WebViewerCache” folder instead, the image fails to display.

Kindly assist.

I don’t think so. The Orthanc WebViewer development is not really active anymore since other more feature rich viewers are available like StoneWebViewer or OHIF.

Alright, thank you for your response.
I have just been working on a plugin that extends the Orthanc WebViewer as part of my school project, and right now that’s the only flaw in the workflow. I am worried about switching to a completely new viewer at this stage, so If there is anything at all that you think could help with regards to the cache issue (given the experience you have with the Orthanc ecosystem) , I will appreciate the help.

Thank you.