WebP is currently missing from the list of supported mimetypes.

It's an open source image format, using VP8 or VP8L for image data and RIFF for containers.

Previously, adding webp support was considered in 2011, but wasn't well supported at the time: ( https://bugs.python.org/issue11362 ). In 2019, WebP now enjoys support in major browsers and OSes. Its sister video format WebM was added to mimetypes in 2016 ( https://bugs.python.org/issue16329 ) and has similar support to WebP.

WebP homepage: https://developers.google.com/speed/webp
WebP source: https://chromium.googlesource.com/webm/libwebp/
RIFF container spec: https://developers.google.com/speed/webp/docs/riff_container
VP8 format spec: https://datatracker.ietf.org/doc/rfc6386/

Similar to previous discussions having an IANA registration would improve the acceptance of the patch to add it. It's still not listed at https://www.iana.org/assignments/media-types/media-types.xhtml

Okay, I've opened a bug with WebP team regarding IANA registration: https://bugs.chromium.org/p/webp/issues/detail?id=448

For what its worth, WebM was added without an IANA registration as a de facto standard. Approval was given in this 2014 comment: https://bugs.python.org/issue16329

To help support the recognition of WebP as a de facto standard, the image format is currently seeing about the same amount of usage on the web as BMP images, and has seen sharp growth this year, approximately tripling in usage. Data from W3: https://w3techs.com/technologies/details/im-webp

Please let me know if there's any data I can provide, or anyone specific I should contact regarding approval.

Sorry, amendment to my last comment: the WebM approval without IANA registration was in msg232095 of https://bugs.python.org/issue16329

I'm +1 to add it in common types, because webp is really de-facto standard.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types

If no objection, I will merge this in next week.

Very uncomfortable to work with webp without it And webp is now pretty hyped due to Google's Core Web Vitals update. 
E.g. pretty popular Django Storages relies on python native mimetype module, so because of this bug it always sets default application/octet-stream to AWS headers, so in the end when users click Open Image on new tab they get webp downloaded 🤣🤣🤣
 

https://github.com/jschneier/django-storages/blob/6071ac3410ee6ecd498b5691f1b45d376374bffc/storages/backends/s3boto.py#L391