Squash: Batch image resizing doesn't get much easier
Here's how it works. You download and unzip the executable application for Windows, Mac, or Linux. Choose your output directory, add some files, and choose your resizing options. When you click resize, Squash will spit out your new images in your output folder in no time flat.
We kind of wish you could tell Squash to resize all of your images so that they're 200 pixels wide. But you can't. Instead, it lets you shrink or blow up your images by percentages. So if you had a 400 pixel image and a 200 pixel image and you want to cut them both in half, you'll wind up with a 200 pixel and a 100 pixel image. But the program is open source, so if anyone has some free time on their hands and wants to add our dream feature, we'd love you forever. Or at least write an update.
Squash will convert PNG, JPG, and BMP images.