Cimo – A Fresh Approach to Media Optimimization

Cimo is a lightweight media optimization plugin for WordPress that processes images in the browser during upload, without relying on server resources or external APIs. When a user uploads an image, Cimo compresses, resizes, and converts it to the WebP format before it ever reaches the Media Library, resulting in faster load times and reduced storage usage without placing any additional load on the server.

Cimo offers a free version with no quotas, limits, or recurring fees.

The plugin also includes configurable settings for maximum image dimensions, WebP quality, thumbnail generation, and disabling WordPress’s native image scaling behavior. A metrics dashboard in the admin area provides insight into total space saved and compression ratios. The plugin supports all major browsers except Safari, where images upload normally without optimization. Cimo is compatible with WordPress 6.x+, modern PHP versions, and virtually all builders and block-based editing workflows.

A recent update added a before-and-after comparison, and if the compressed image is larger (WebP does that sometimes), it is ignored.

The biggest caveat is that it does not optimize existing images already in the Media Library — only new uploads are processed — and the free version focuses strictly on images, leaving video and audio optimization to the paid upgrade. Another limitation is the lack of optimization in the editor when dragging or pasting an image into the post.

On X, Nicholas Arce proposed an idea for a plugin that caught the eye of the Cimo developer, and hopefully, a collaboration is in the works. I suspect AVIF support will be added in the future.