Verify the actual file
Open it with a trusted local image application. If it fails there, download it again from the legitimate source. If it opens, export a fresh copy in a format the search service explicitly accepts.
Check the basics
- Confirm the file is an image rather than a shortcut.
- Export instead of merely renaming the extension.
- Check the resulting file size.
- Preview orientation and crop before upload.
A browser's “save page” command can create HTML even when the page displays a photograph. Selecting the actual image file avoids confusing a document with the image itself.
Do not overconvert
Repeated conversion can degrade detail while leaving the real issue unresolved. Return to the original each time you test an export setting. Facehunch accepts JPG, PNG and WebP within its stated size limit; those constraints apply to the actual encoded file, not only its name.
Continue with image-search troubleshooting.