List of constants to add in wp-config.php

The functionality of ShortPixel Image Optimizer can be extended by defining constants on the wp-config.php file. What this means is that we can add several lines on the wp-config.php file to add some advanced features to the plugin.

First, locate the file, which must be on the root of your WordPress installation, and edit it. It is called wp-config.php:

Now, you should add each line that we will detail below, before the line that says

/* That's all, stop editing! Happy blogging. */

We will see an example later.

List of constants


If you have a theme which creates thumbnails that don't have the usual suffix (which is image-WWWxHHH, where WWW is the width and HHH the height of the image) and you want such thumbnails to be handled by ShortPixel too, you should add this line and add all the custom suffixes your theme is creating separated by commas. For example, this specific line will handle the images with the suffixes _tl and _tr, like image-100x100_tl.jpg or image-100x100_tr.jpg


This constant does the same as the previous but treating infixes. For example, custom thumbnails like image-uae-100x100.jpg

This tells the plugin to create double extensions for the WebP image counterparts. Obviously, this is valid only if the WebP option is selected on Settings > ShortPixel > Advanced >  WebP Images. This means that instead of creating image .webp for your image.jpg, the file will be created as image .jpg.webp
define('SHORTPIXEL_API_KEY', '<<your api key here>>');
If you would like to set your API key through the wp-config.php instead of through the settings screen, you can do so with this define. Just replace  <<your api key here>> with your actual API key.
define('SHORTPIXEL_HIDE_API_KEY', true);
In case you need to hide the API key from your settings screen, use this constant. It will appear like this: ************


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