WEBP NGINX QUESTION

I don’t think you use .htaccess files with nginx, but I could be wrong. At any rate, I don’t know how to do this with nginx, but if someone else has some experience in this area, feel free to chime in.

The basic logic should look like this:
1. Does the browser support webp (indicated in the HTTP_ACCEPT header)?
2. Is this file a jpg/png (looking for an extension of jpeg/jpg/png, case insensitive)?
3. Does a file exist with .webp appended to the end of the filename identical to #1
4. rewrite the filename with .webp appended
5. with mod_headers we append Accept to the Vary header
6. we add an image/webp mimetype to the server’s mime-type list (this is something your host should do in a separate config).

I forgot someone once posted this: https://www.lazutkin.com/blog/2014/02/23/serve-files-with-nginx-conditionally/

It worked for them, and the logic looks solid, and mostly matches what EWWW IO does for file-naming.