How Optimized Are Your Images? Meet ImageOptim-CLI, a Batch Compression Tool | Smashing Magazine

Exporting images for the Web from one’s favorite graphics software is something many of us have done hundreds of times. Our eyes fixate on an image’s preview, carefully adjusting the quality and optimization settings until we’ve found that sweet spot, where the file size and quality are both the best they can possibly be.

After exporting the image — usually using a feature called “Save for the Web” — and having gone to all that care and effort, we would be forgiven for thinking that our image is in the best shape possible. That’s not always the case, of course.

In fact, much more data is usually left in such files, data that browsers have to download despite not requiring or even using it, data that keeps our users waiting just a bit longer than necessary.

Thankfully, a number of popular tools can help us optimize images even further, but which should we use? We assumed, for a time at least, that our graphics editing software properly optimized our files, but what do we really know about our image optimization tools?