Smush is WordPress plugin that that allows you to optimize the media files on your WordPress website. The plugin works by compressing the media files with the main purpose is to speed up your website. Smush uses the lossless compression method to make sure the quality of your media files is not disrupted after the compression. Smush supports several media file types that are supported by WordPress, including JPG, PNG, GIF, WebP, SVG, to Iframe.

You can use Smush to compress the existing media files on your WordPress. You can perform whether a bulk compression or an individual compression. After installing and activating the plugin, your media files will be automatically compressed when you upload new ones.

In addition to being able to compress media files under the uploads directory, Smush can also be used to compress media files outside this folder. Smush support integrations with Gravity Forms to allow you to compress media files uploaded via a Gravity Forms-powered form. If you use the NextGen Gallery plugin, you can also compress your images directly via the NextGent Gallery settings thanks to the native integration offered by Smush.

In addition to the main features above, Smush also offers other supporting features, including the ability to convert JPG and PNG files into WebP. Also, it comes with advanced lazy load feature for media files. You can select which type of media files you want to apply the lazy load to. You can even select the type of images (content, widget, post thumbnail, gravatar) as well. For more advanced speed optimization, you can also activate the built-in CDN service offered by the plugin.

Smush itself is developed by Incsub, LLC — the company behind WPMU DEV.