how do I allow data:image/ in img tag?

[Xyncgas]

I am pretty sure this gets sanitised by default

[mganss]

Call sanitizer.AllowedSchemes.Add("data");

[Xyncgas]

Thanks

[tiesont]

Seems worth mentioning that this specific question is answered in the wiki: https://github.com/mganss/HtmlSanitizer/wiki/Examples#ex2-allowing-data-uris

Not saying it's wrong to ask, but it's always a good idea to check the documentation and examples.

[isaacbromberg]

Wouldn't it make sense to make it more precise so that the allowed schema would be:
sanitizer.AllowedSchemes.Add("data:image");

We have got security advice to allow only images in our form.

[mganss]

The scheme is data, image/png is the MIME type of the data. If you want more control over the allowed URLs, you can use the FilterUrl event.