FileOptimizer is an open source, portable, 64-bit compatible app for Windows that can cut down the file size of a mind-boggling 200+ file formats by recompressing and optimizing them. The app itself doesn’t do the heavy lifting, but rather calls one or more of over two dozen included optimization tools to get the job done. Whether it be an image, or an Office document, or a PDF, or even an EXE file, FileOptimizer handles them all. Its most popular feature is obviously lossless/lossy optimization of PNG, JPG, and GIF images, which results in smaller files ready to be shared on blogs and social networks.
The interface is a tad utilitarian and looks out of sorts in Windows 8 and 10, but really, that’s all the criticism that can be made of the app.
UPDATE: We have found that while optimizing PNG images, FileOptimizer uses about a dozen different tools together to get the smallest possible file. That sounds great in theory, but it also takes obscenely long times to optimize small PNG files (<100KB in size). We have singled out the tools that take up majority of the time, but don’t contribute all that much to size reduction, and would recommend you to delete them from the Plugins32 and Plugins64 folder in FileOptimizer,
After you remove these files, FileOptimizer will optimize the PNG files using the remaining tools, and the process will be much faster which still resulting in an equally smaller file. Every time FileOptimizer updates, it’ll add these files back to its plugins folder, so you have to keep a list and remove them after every update.
We also recommend turning on “lossy optimizations” for PNG to achieve massive reductions (up to 80%) in file size without noticeable difference in quality.