Topic: question regarding image type

so i found out an image i had uploaded as a jpg has a png version but the png and jpg have the same size, should i replace the jpg with the png regardless?

It's not quite black and white, but in general, yes, a png of equal resolution (or even lower, to an extent) is usually superior to a jpg. That's assuming the png version isn't just a jpg converted to a png, though.

scth said:
It's not quite black and white, but in general, yes, a png of equal resolution (or even lower, to an extent) is usually superior to a jpg. That's assuming the png version isn't just a jpg converted to a png, though.

in this case it's a twitter jpg vs a deviantart png

watermelons said:
in this case it's a twitter jpg vs a deviantart png

DeviantArt would tend to be a better source as compared to X/Twitter, see howto:sites and sources.
However, you will still need to do your due diligence in extracting the highest quality version from both and then comparing it.

What we tend to see as superior is:

• File format: (Actual) PNGs over JPGs. It must be specifically encoded as a PNG by the artist, which cannot be simply done by renaming it.
• File size: Not a reliable factor, but larger file sizes tend to suggest more actual image data being stored. PNGs will also tend to be larger than JPGs, as the latter compresses lossily.
• Image Dimensions: Also not a reliable factor, but usually the larger one is the better one.
• Image Quality: The most important determining factor, we want things to be of high quality. That means no visible compression artifacts (which would normally be absent in PNGs) or any other flaws.

I would also highly recommend you to read e621:Image Quality to learn more about how we compare the quality of images.