Online Convert - Convert files like images, video, documents, audio and more to other formats with this free and fast online converter.
Ralpha Image Resizer - High-speed image batch conversion tool
Pixillion - Easily convert photos and images between file formats in a batch or single file. Compress, rotate, resize, or add text and watermarks to any file. Free download.
ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
FileStar - With FileStar you can "do anything with any file".
Caesium Image Compressor - Compress your pictures up to 90% without visible quality loss.