Caesium is an image compression tool.

Image Tuner is a free batch image resizing, renaming, conversion and watermarking software with a super-intuitive and straightforward interface.

Phatch (PHoto & bATCH) is a raster graphics editor used to batch process digital graphics and photographs. Phatch can be used on the desktop as a GUI program …

PNGGauntlet is a PNG compression app for Windows.

XnConvert is a powerful and free cross-platform batch image processor, allowing you to combine over 80 actions.

FastStone Photo Resizer is an image converter and renaming tool that intends to enable users to convert, rename, resize, crop, rotate, change color depth, etc…

ImBatch is a batch image processing software.

PhotoBulk is an easy-to-use batch photo editor. Watermark photos, Optimize and Rename photos at once.

Radical Image Optimization Tool (RIOT) is a free image optimizer that will let you to visually adjust compression parameters.