Smush.it is an image optimiser developed by Yahoo! that lets you decrease image file sizes without losing image quality. If you’re running WordPress, there is a plugin that’s optimises images on the fly when you upload them. WP Smush.it takes just moments to install and can make a big impact on the performance of your website.
How does it work?
Every image you add to a page or post will be automatically run through Smush.it behind the scenes. You don’t have to do anything different.
N. B. In some cases GIFs should be replaced with PNG files. You can control this behaviour on the Options page. It is off by default.
Smush.it vs PunyPNG
We use Smush.it because it comes in an easy to use WordPress plugin that optimises images uploaded. PunyPNG however compared their compression engine against Smush.it in a recent test and achieved a 41% compression rate, while Smush.it only achieved 14%. So if you want to optimise the websites main template images it would be worth checking out PunyPNG as well as Smush.it.
Other image optimisation tools
There are many image optimisation tools available, here are just a few: