Dear PowerArchiver users,

We are happy to announce that we have added a jpeg compression codec to PowerArchiver 2017.

After testing several available jpeg codecs, together with our internally developed one, we have decided to add the Lepton codec as the jpeg codec in our advanced codec pack (.pa format).

Among several candidates, Lepton has shown the best combination of good compression, speed and robustness. Due to its usage in commercial projects, it is well tested in real world scenarios and that played an important part in our decision to implement it.


For test examples, we have downloaded images from the most popular image sites such as Flickr, 500px, Google photos and few others. We compared our results to WinZip jpeg zipx codec as well as WinRAR, which has no support for jpeg, so it does not compress them at all (to compare how every other archiver without jpeg codec does). It seems that WinZip does not support compressing images from one of the above mentioned image services and that accounts for most of the difference in file size. With other supported images, the difference in file size was down to 2%. None of the jpeg compression codecs support all of the various parts of jpeg standard, but Lepton proves to be pretty good at supporting the most used standards. You can learn more about Lepton in a blog post from it’s creators at Dropbox (thanks!).

PowerArchiver 2017, with the Advanced Codec Pack (.PA), is available to our most dedicated users with an active PowerArchiver Select plan, as a preview version. We hope to have the first public release arriving very soon.