Loss of quality when posting on LINE Webtoons?

[honeyandcreambutter]

I noticed that the quality of the webtoons is different when I post on Tapas compared to LINE. And it's not just the fact that images are blurrier, LINE somehow desaturates the colours as well. So, for example, my character's eyes are purple and on Tapas it looks perfectly fine but, on LINE it looks gray Anything with a dark background with something red above it becomes incredibly pixelated as well.

Does anyone face this same issue? How do you work around it? Does it have anything to do with uploading JPEG vs. PNG images (sometimes I use PNG but on rare occasions, I upload it in JPEG format) or does LINE just compresses the image too much? Also, before you suggest saturating the colours to compensate, I'm worried that it will look off on Tapas if I do so

[PaleOcra]

Make sure that you resize your image width to exactly 800px. Anything less than that results in lower quality

[honeyandcreambutter]

I do! I even use a trick where you start from 1200 px and then resize it down to 800 px to prevent blurry images when you send it in for cropping