While I don't use a lot of images on this blog, I do make art and take photos that I sometimes like to share online, and think it is important to make sure that images are optimised properly, so they don't take up a huge amount of space.
Since I have joined piclog it is especially useful to make photos lighter in size, to prep them for upload (and further compression!).
Krita – the app I use to make art – has its own web optimisation settings, however it is TinyPNG that provides the best results.
TinyPNG is a free compression tool that uses smart lossy compression techniques to reduce the file size of PNG and JPEG files. By selectively decreasing the number of colours in the image, fewer bytes are required to store the data: the result is a nearly identical image that is much smaller, taking up less bandwidth and allowing sites to load faster.
It is possible to use the app directly on its website, compressing up to 20 images at the same time. Thee tool comes with scripts and plugins for Wordpress and other platforms and apps, and I currenly use this CLI script.
I've been using TinyPNG for a long time now, and I would definitely suggest it to anyone posting images online: it takes little time to use it and it makes a huge difference.