The WP Squish plugin helps to reduce the amount of storage space consumed by your WordPress installation through the application of user-definable JPEG compression levels and image resolution limits to uploaded images.
- Set a resolution (width and height) limit for the “full size” images; images exceeding the limit are resized when uploaded.
- Customize the compression level (on a scale of 1 to 100) for each of the downsized copies of a JPEG image generated by WordPress when it is uploaded.
- Optionally recompress the full size versions of all JPEG images when they are uploaded.
Screenshot from v1.0.0