>>1272139Right click on folder > Properties > Advanced > Compress contents to save space. It will slow down access to the file slightly but will also make it a bit smaller without preventing programs from using it.
That method does not change the data at all (the quality doesn't decrease). Basically the only other methods that won't decrease quality are storing things in 7z files and using UPX on dlls/exes.
None of those methods will do anything to decrease the size of images or videos. If you want to make those things smaller you will have to re-encode them which will result in a quality reduction.
(note to autists, this is all drastically simplified, yes i know what lossless/lossy means)
