Update (2017): ShortPixel keeps ICC profiles, because it is essential for proper rendering of some images. Not much compression is gained usually (~1%) while the risk of altering the colors of the images is considerable.
EXIF data is a collection of various pieces of information that is saved in the image file by the device that created the image (camera, processing software, etc). Examples of types of information include: GPS position, date and time, author name, camera/phone model and shot settings, ICC color profile, even some custom thumbnails, which are used by the cameras to display the image on the camera’s screen. All this info can ad up to a significant amount of kilobytes.
We at ShortPixel try to reduce the size of images by compressing them and removing all the extra data that doesn’t reflect visually in the optimized image, including the EXIF tag (but preserving the ICC profile) . While we’re quite good at this, sometimes the EXIF profile contains data that can be very helpful if you are, for example, a photographer.
For these specific needs, we added,in our latest version of ShortPixel image optimization plugin, an option to keep EXIF profile data. While adding this new feature we were curious to see how much of a difference in terms of image size could make keeping the EXIF profile data.
So we’ve chosen a sample of 7,646 JPEG files from the files we optimize with ShortPixel and optimized them in both ways.
The resulting files have:
•791.144MB when we kept all the EXIF profile data
•723.552MB when we removed the data.
That means removing EXIF/ICC image data leads, on average, to files that are 8.5% smaller.
You might want to keep this in mind when making a decision whether to keep or remove EXIF and ICC profile data.