Images to WebP

FAQ

Plugin requirements

It should work almost everywhere 😉
PHP 5.6 or higher
GD or Imagick extension with WebP support
Enabled server modules: mod_mime, mod_rewrite

WebP images stored location

WebP images are generated in same directory as original image. Example:
original img: /wp-content/uploads/2019/11/car.png
webp version: /wp-content/uploads/2019/11/car.png.webp

How to get original image from the browser?

Just add ?no_webp=1 to the URL and original JPG/PNG will be loaded

How to check if plugin works?

When you have installed plugin and converted all images, follow these steps:

1. Run Google Chrome and enable Dev Tools (F12).
2. Go to the Network tab click on Disable cache and select filtering for Img (Images).
3. Refresh your website page.
4. Check list of loaded images. Note Type column.
5. If value of webp is there, then everything works fine.

NGiNX and Apache together

If you have some proxy setup or some other combination of NGiNX and Apache on your server, then probably .htaccess changes won’t work and you will need to ask your hosting provider to disable NGiNX direct processing of image static files.

Apache .htaccess

Plugin should automatically update your .htaccess with needed rules.
In case it’s not possible to write them automatically, screen with instructions will appear.
Anyway, here is how it should look like:

<IfModule mod_mime.c>
    AddType image/webp .webp
</IfModule>

<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{HTTP_ACCEPT} image/webp
    RewriteCond %{REQUEST_FILENAME} "/"
    RewriteCond %{REQUEST_FILENAME} "\.(jpg|jpeg|png|gif)$"
    RewriteCond %{REQUEST_FILENAME}\.webp -f
    RewriteCond %{QUERY_STRING} !no_webp
    RewriteRule ^(.+)$ $1\.webp [NC,T=image/webp,E=webp,L]
</IfModule>

NGiNX config

After you activate plugin, screen with instructions will appear.
Anyway, here is how it should look like:

You need to add this map directive to your http config, usually nginx.conf ( inside of the http{} section ):

map $arg_no_webp $no_webp{
    default "";
    "1" "no_webp";
}

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

then you need to add this to your server block, usually site.conf or /nginx/sites-enabled/default ( inside of the server{} section ):

location ~* ^/.+\.(png|gif|jpe?g)$ {
    add_header Vary Accept;
    try_files $uri$webp_suffix$no_webp $uri =404;
}

ISP Manager

Are you using ISP Manager? Then it’s probably not working for you, but no worries, you just need to go to WWW domains and delete jpg|jpeg|png from the Static content extensions field.

Delete all generated WebP images

There is no button to do that and it will also not delete generated WebPs automatically when you deactivate the plugin, but if you really need this, you can run some shell command to achieve this:

find . -type f -name "*.webp" -exec bash -c 'if [ -f "${1%.webp}" ]; then echo "Deleting $1"; rm "$1"; fi' _ {} \;

This will find all the files with a .webp extension and if there is similar file with the exact filename, but without the .webp extension, then it will delete it.