PNGOut is like it is said the best out of all the single programs I have used. I use PNGGauntlet too ,with OptiPNG and DeflOpt turned off, since they make the process much longer and the gained size is insignificant. PNG Optimizer though is what I use the most, since it is faster than PNGOut. In the
I did a test on a batch if 15000 pictures which though a lot were small. The results are under and I added the size on disk, just cause it is on the info tab
Original
Size of files: 397 MB (417,167,186 bytes)
Size on disk: 428 MB (449,069,056 bytes)
PNG Optimizer - 37 minutes
Size of files: 288 MB (303,028,157 bytes)
Size on disk: 326 MB (342,130,688 bytes)
PNGOut - 50 minutes
Size of files: 314 MB (329,867,863 bytes)
Size on disk: 351 MB (368,250,880 bytes)
Again, the pictures were tiny, but as you see PNG Optimizer was better than PNGOut. In larger pictures I have tested, PNG Optimizer is indeed much much much faster, but PNGOut gives a better compression.
If I want the absolute tiniest lossless PNG I can get, I use FileOptimizer, with itâs PNG settings being to lossless (I untick the lossy option). FileOptimizer is the best when it comes to size and probably the slowest. After checked itâs running processes it seems it run the following optimizers, in order; PNGOptimizer, TruePNG, ECT, PNGOut, OptiPNG(this takes the longest), Leanify, pngwolf, pngrewrite, advpng, DeflOpt, defluff and once more DeflOpt. I wish I could turn off OptiPNG since like in PNGGauntlet it makes the process 20 times slower (literally) and it rarely is worth of the wait. From a test on a larger file, the times were like this;
PNGOptimizer 2 seconds
TruePNG 34 seconds
ECT 0.5 seconds
PNGOut 14 seconds
OptiPNG 2 minutes 23 seconds
Leanify 1 minute 6 seconds (it did make it ever so slightly smaller)
pngwolf 37 seconds
pngrewrite 0.5 seconds
advpng 17 seconds
DeflOpt+defluff+DeflOpt in the end took together 2 seconds
FileOptimizer is definitely the best Lossless, but also lossy PNG Optimizer. For lossy, it gives equal results with sites like my favorite Compress PNG site. Sadly though OptiPNG makes the process so lengthy, that for me it is better to upload it there and instead XD