To view the Advanced options, first Enable Ludicrous Mode:
The advanced settings of EWWW really let you customize the plugin for your specific site and for your unique workflow, and additional settings are available in the Overrides.
This is not a user configurable option, but it is worth explaining how background optimization is enabled (or not). When you first activate the plugin, it will send a test packet to see if your server supports background optimization. Essentially, the server is sending a packet to itself, but some security plugins don't allow this, so that's why the plugin has to verify that such a request will work. If the packet is received, and has not been altered, the background optimization "option" is automatically enabled. If background mode isn't working for your site, check out our troubleshooting tips.
EWWW IO has a folder scanning feature that will look for images from your theme, and a handful of pre-configured folders for plugins like buddypress and meta-slider. To make sure these images are optimized regularly, there is an option to schedule optimization of these images on an hourly basis.
Include Media Library Folders
If your theme or some plugin is generating images in the media library folders, but not registering them properly in the attachment metadata, you can tell EWWW to include the most recent 2 folders in any scans. This applies to Bulk Optimization and Scheduled Optimization. For example, if it is October of 2031, then the plugin will scan wp-content/uploads/2031/09/ and wp-content/uploads/2031/10/ and optimize any images within those folders.
As of WordPress 5.3, any image that is wider than 2,560 pixels will be scaled down and will have the original upload stored alongside the scaled version. The original image is preserved for image resizing and thumbnail regeneration, but in order to save on storage space, you can use this option to have the original images optimized also.
Folders to Optimize
If you have images elsewhere in your WordPress folder, you can add those to the Folders to Optimize setting. If new images in a folder are being automatically optimized, then you only need to put the folder in here once, run a Bulk Optimize, and then remove the folder from the settings. You can verify what is being optimized by visiting the EWWW IO Tools page, and clicking the Show Optimized Images button. Otherwise, when a folder isn’t being auto-optimized, you can leave the folder in this setting and enable Scheduled Optimization to look for new images every hour.
It is important to enter full file-system paths, not URLs or partial paths. The path to your WordPress folder is given directly above the textarea for this setting as a reference point. So if it says /var/www/wordpress/, then you should enter paths like /var/www/wordpress/wp-content/spiffy-plugin/images/
When running a bulk optimize, the scanner searches for the same images as scheduled optimization in addition to the Media Library images, so if you want EWWW to ignore your theme, or some other folder, you can configure that here. It is not necessary to enter full paths for this setting, but any image that matches something entered here will be skipped. For example, if you enter '2015' because you don't want old images optimized, it will not just skip the 2015 uploads folder, but ANY file that might have 2015 in the name (which might be OK for you, but be careful with that).
JPG Quality Level
It is not recommended to go any lower than 50 or higher than 92. Anything above that is just wasteful and will yield no visible improvement. Read more about JPG quality.
WebP Quality Level
Similar to the JPG quality, this is neither a percentage, nor linear. This quality metric tends to be better than JPG, such that a lower quality level can be used for WebP to achieve similar results.
AVIF Quality Level
As the AVIF format is generally superior to WebP and JPG in terms of compression and quality, an even lower quality level may be used to achieve comparable visual results.
This is a reference to the 1987 movie Spaceballs, plaid makes an appearance at 3:30.