@worldsendless Going from (properly) lossy to lossless is always going to result in a larger file, as I believe the lossless part picks up any artifacts etc from the lossy compression, which happens to be the hardest part to compress.

Maybe dwebp is just really bad at encoding PNG's? In that case pngcrush will make the file smaller.

You might also try converting with ImageMagick.


Really, you want to start with lossless and then decide if you want to move to lossy, not the other way round.

If you have quite a few images in webp, you should probably just leave them in webp, as they aren't going to lose quality unless you re-encode them.