Very Good, but a caution!

This is a very useful small program and what it does it does well.

BUT as for the caution and suggestion. Dont rely on this if high quality storage really matters. JPEG is itself a lossy compression algorithm which by inference makes this also a lossy compression. Up to a point, thats okay in that JPEG allows the storage of a lot of picture data in a relatively small space. This app can take that further in file reduction without significantly increasing image loss. It may or may not be noticeable depending on how you are using the image. QUALITY

JPEGmini is not at all exaggerating what its app does. This is an optimized JPEG and it is aimed at PERCEPTUAL quality and that should be equal or very close to it.

One reviewer said he could see very small differences on a Retina screen, which is about all I use. What I do and recommend to anyone who has photographs of importance to themselves or their family is to store first generation ca mera images in a safe, redundant way, whether it be mirrored disks, RAIDS, or whatever. Storage is cheap -- at least when its not SSID in a new Mac. I would keep the original file and not edit that copy more than necessary. There is in JPG an inevitable degradation with each generation, the degree depending on the quality setting, the size and quality are related (talking JPG here). Use a straight copy to edit from; generally you want to be working as close to the first generation as you can. You may want to make a master edited copy (and keep it instead, but treat it as an original).

This wont matter as much if you primarily want pictures for posting or mailing and dont ever intend to make prints, in particular large prints.
This may seem to be trivial, because most photos for most people arent critical. As a retired professional most of what I shoot starts as RAW files and high quality derivitive files, including jpgs. I still license images for publications and JPGs work well for sending to publishers, etc. Large prints require high quality -- and this may or may not work with a high quality jpg. Cant say.

But Ive already seen that this is a neat program for uploading to DROPBOX or sending through email where it has some real advantages. Reality is that the printed image is not as important as it once was (just dont forget it entirely) and this is one of those near programs that makes the electrons move faster.

older dog about JPEGmini