Trouts GIF Optimizer shrinks GIFs without any noticable reduction of picture quality. Just drag-and-drop files then Save. Supports animated GIFs.

Trouts GIF Optimizer is a free little portable utility which can quickly compress the GIF image up to 90% of it's original size while keeping the quality intact.

This software will even convert other graphics to optimized GIFs:
* Bitmaps (*.bmp)
* JPEGs (*.jpg; *jpeg)
* Icons (*.ico)
* Metafiles (*.wmf; *.emf)

Trouts GIF Optimizer New Features:
1. create even smaller GIFs
2. cut, copy and paste graphics to / from the Windows clipboard
3. color reduction to create much smaller GIFs
4. sort graphics in batch optimizations by name, size, bytes saved etc
5. preview to compare the original graphics with the optimized GIFs
6. Recursively search for graphics through folders and their subfolders

Please Note: It won't necessarily compress every GIF image, such as the already compressed GIF file.

The license of this software is Freeware, you can free download and free use this image optimizer software.