XnView Software

On the Input tab the Add files... dialog has an option to specify the extension of the files to be added.

However, the Add folder... dialog currently does not include that option, would it be a useful addition?


Reference:

Water mark only Jpegs leaving .Cr2 in same folder?

in 'quick search' field, you can enter .jpg, and 'remove unfiltered', so that you'll have only jpeg files