Serving WEBP with nginx conditionally.

nginx-webp-sample.conf

user www-data;

http {

  ##
  # Basic Settings
  ##

  sendfile on;
  tcp_nopush on;
  tcp_nodelay on;

  # IMPORTANT!!! Make sure that mime.types below lists WebP like that:
  # image/webp webp;
  include /etc/nginx/mime.types;
  default_type application/octet-stream;

  gzip on;
  gzip_disable "msie6";

  ##
  # Conditional variables
  ##
  
  map $http_accept $webp_suffix {
    default   "";
    "~*webp"  ".webp";
  }

  ##
  # Minimal server
  ##
  
  server {
    listen 80 default_server;
    listen [::]:80 default_server ipv6only=on;

    root /usr/share/nginx/html;
    index index.html;

    # Make site accessible from http://localhost/ or whatever you like
    server_name localhost;

    location ~* ^/images/.+\.(png|jpg)$ {
      root /home/www-data;
      add_header Vary Accept;
      try_files $uri$webp_suffix $uri =404;
    }
  }
}

@Garistar I am not sure your approach is correct as is:

• I am advocating against using rewrite. See the referenced blog post.
• The gist has no rewrites.
• Your rewrite expression will be triggered on files like nopng, because it misses a dot in it. And it has some other minor problems.
  • But I do understand your point.

The reason why in my original code I add a suffix instead of manipulating names is actually simple: because I use webp for png and jpg removing the original extensions opens up for a potential name clash. Compare:

• image.png ⇒ image.png.webp
• image.jpg ⇒ image.jpg.webp

with:

• image.png ⇒ image.webp
• image.jpg ⇒ image.webp

I create .webp files statically using a utility, I don't want to deal with possible overwrites.

On top of that my actual code (not the toy one in the example) can serve multiple compressions:

• brotli, zopfli, and gzip for text files + original uncompressed files, if the precompressed versions are missing
• webp, zopflipng, and png for png-style images
• webp, guetzli, and jpg for jpg-style images

Nowadays I am considering adding avif to the list.

That's why a name manipulation is not a priority to me.

If it is important it is possible not only update file names but serve files from:

• Different folders.
• Different domains (e.g., different AWS buckets).

Doing that will help with potential name clashes as well.

@uhop
I create .webp files statically using a utility, I don't want to deal with possible overwrites.

If you serving a WordPress site, you may use Warp iMagick plugin with your nginx configuration.

Can I use this without .webp files?

@h2kyaw You can. See the comments above explaining my approach. But you can obviously update the recipe to suit your needs.

BTW, WordOps Control Panel for Nginx Server and WordPress Sites is already configured for WebP and AVIF.

@pmochine

For example: picture.jpg => picture.webp and not picture.jpg.webp

Imagine uploading picture.jpg and picture.png into same directory. What would happen?