As the developer of Optimus we get the following feedback quite often: “…Optimus HQ only reduces my PNG image sizes by 10-20%. That’s nothing…” True, an optimization value in the high double-digits seems solid and impressive (such “heights” are achievable depending on the picture and the amount of metadata). For JPG images however, Optimus compresses them using lossy compression (resulting in larger savings) as opposed to lossless compression as it uses for PNGs.
But even values in the lower area are anything but bad; after all, for PNG images we are talking about a lossless optimization (not compression) of images here. That means: you receive images that are smaller by “just about” X % at the same level of (visual) quality. And since you are usually using several pictures per website, the optimization gains add up. Therefore, optimizing images always makes sense.
We like to compare the lossless method with new Web technologies such as Zopfli Compression Algorithm and W3C – WOFF File Format 2.0 which have become standards thanks to their compression gains and have been implemented by Google on each platform as far possible (even in Chrome). Here’s the kicker: Zopfli promises to deliver an output file that is 5% smaller, WOFF2 achieves an average of 15%. All these results appear minimal at first sight, but if you add them up you get noticeable savings without any adverse effects or losses in quality—all the while helping performance.
If you adjust all possible screws to improve performance, you end up with a nimble website or app. That is the idea behind Optimus.