Thursday, January 7, 2016


ImageOptim is a free app for Mac that applies lossless compression to images. Meaning: ImageOptim reduces file size without compromising image quality — useful when storing images, useful when posting images online. The app is ridiculously easy to use: drag files or folders to its window or right-click on a single image or a group of images to apply compression.

Here are two Slouch Gavitskys. Can you see any difference?

[Zippy, December 21, 2015.]

Slouch-left weighs in at 78 KB; Slouch-right at 24 KB. Image after image, those differences add up. I’ll be using ImageOptim often. Even its shortened (compressed) name is appealing.

There are many image optimizers for Windows. Any recommendations?

A related post

comments: 5

Frex said...

Cool! Thanks, I am going to try this. I often reduce in iPhoto the size of photos to post, but this looks like a better way.

Michael Leddy said...

All ImageOptim does is reduce the file size, so you could reduce the dimensions in iPhoto (or Preview) and then apply ImageOptim to get a smaller file. With Blogger, a good trick to get the best image quality is to make sure that the HTML for the posted image includes s1600 and not s400 or s200 or anything else. You can change that number by hand to get better image quality. Images uploaded at their original size have s1600. I always upload the original size, and if I need to then make it smaller, I change the s number back to 1600.

Michael Leddy said...

Geekin’ out a bit . . . beg pardon.

Matt Thomas said...

Great find. I look forward to using this app to do my part in fighting what Maciej Cegłowski calls “the website obesity crisis.”

Michael Leddy said...

I can’t believe that I’ve only now found out about ImageOptim. At least I’m not as late to Maciej Cegłowski’s talk. Thanks for that. (I like Pinboard a lot.)