Skip to content

Instantly share code, notes, and snippets.

Last active November 3, 2023 12:09
  • Star 31 You must be signed in to star a gist
  • Fork 11 You must be signed in to fork a gist
Star You must be signed in to star a gist
Save uhop/9177153 to your computer and use it in GitHub Desktop.
Serving WEBP with nginx conditionally.
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;
Copy link

Thanks for both the gist and the blog post. They were really helpful.

One note: as far as I can tell, this can be simplified a bit. I did the following:

  1. Removed the map directive entirely
  2. Re-wrote try_files like this: try_files "${uri}.webp" $uri =404;

So now we're just doing a simple string interpolation instead of a map lookup.

This is convenient, because all of the relevant configs can now be placed within the server block. (Previously, I got errors when I deviated from what you did here and tried to put the map directive in the server block.) This might make it possible to touch fewer nginx config files than would otherwise be necessary.

It's possible that I'm overlooking something here, but as best as I can tell, this all works OK.


The problem of your conf is one:

You are now, serving webp for 100% of users. webp is only visible (or should be) on Chrome or other more recent browsers. If you try your config on a old browser, the image will show with error... That why the MAP use the variable $http_accept :)

Copy link

pmochine commented Oct 8, 2019

Btw guys, thank you! With the help of: I could make it for me better.

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

Copy link

ghost commented Jan 18, 2021

Since you are using the regex on the rewrite, just look at what's actually is doing.
You can just do
rewrite (.*).2 $1.webp break;
This one seems greedy to me, didn't test it, but as well you can do:
rewrite /^(.*?)(png|jpg)$ $2.webp break;
So you can work with the regex groups.

Copy link

uhop commented Jan 19, 2021

@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.pngimage.png.webp
  • image.jpgimage.jpg.webp


  • image.pngimage.webp
  • image.jpgimage.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.

Copy link

ddur commented Aug 30, 2021

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.

Copy link

h2kyaw commented Dec 25, 2021

Can I use this without .webp files?

Copy link

uhop commented Dec 25, 2021

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

Copy link

ddur commented Feb 18, 2022

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


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

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

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment