JPEGmini is a Mac utility designed to help you reduce the file size of your JPEG images. This type of programs might prove to be of good use to professional photographers who are dealing with immense collections of large-sized images and wish to easily compress the photos without losing their quality in the process.
Before using JPEGmini on your Mac, I'd suggest you to first configure its settings according to your needs as it will automatically start compressing the data immediately after importing the images. You can alter the resolution of your photos and change the output directory if needed.
To use this tool simply drag-and-drop your JPEG files over its interface and the program will take care of the rest. Once the process is complete, the utility reveals the amount of disk space it managed to reclaim.
The only aspect you need to consider before buying JPEGmini for your computer is that its Pro edition provides you with more features (for example, it includes plug-ins for Adobe Lightroom and a Photoshop).
So, it's up to you to decide which program edition is the best for you, based on your needs. Either way, both give you access to quality output files and work perfectly.