Something I've always been wondering,
That I'm just now getting around to asking.
I know the surface answer is because they've
been converted into JPEG and transparency
isn't a thing with JPEG. ╹‿╹)

But with that said,
I guess the title should be:

"Why do thumbnails convert PNGs (and on a low-key note GIFs) into JPEG?"

But I'm getting sidetracked,
Sorry about that ◠‿◠)

• Is it for processing reasons?
• Are JPEGs easier to load than PNGs?
• Or is it for another reason?

For anyone more familiar with this kinda thing, I would Love to hear what you have to say about this.
Would be super neat to have this long-lived pet pev put to bed!

Notkastar said:
Something I've always been wondering,
That I'm just now getting around to asking.
I know the surface answer is because they've
been converted into JPEG and transparency
isn't a thing with JPEG. ╹‿╹)

But with that said,
I guess the title should be:

"Why do thumbnails convert PNGs (and on a low-key note GIFs) into JPEG?"

But I'm getting sidetracked,
Sorry about that ◠‿◠)

• Is it for processing reasons?
• Are JPEGs easier to load than PNGs?
• Or is it for another reason?

For anyone more familiar with this kinda thing, I would Love to hear what you have to say about this.
Would be super neat to have this long-lived pet pev put to bed!

Also I wish everyone reading this an amazing day! Thanks for stopping by ◠‿╹)~★

I think thumbnails just don't register as being transparent

Thumbnails and previews are supposed to be just hint of what the image is before you open it, so the key for those is to be small, not accurate. JPG is widest supported lossy format so that is best way to generate low filesizes which everyone can see, meanwhile PNG files would be massive and would make the pages load several seconds slower.

There are lossy formats which do support transparency like WebP, however the support is so low that many users would be on page with no images to be seen.

Versperus said:
I think thumbnails just don't register as being transparent

They do, but as JPG does not have transparency support, it simply fills the transparency with first color on palette. This is why images have transparency filled with black instead and some GIF files can have some random background color.

Versperus said:
I think thumbnails just don't register as being transparent

Oh, Good one dood! Honestly, haven't even considered,
Since they also work as links to the original art.
Transparent links MAY be a thing but I'm not 100% on that ╹ ╹)

Edit:
Commented just before I got a chance too, Dood ◠‿◠)

Mairo said:
Thumbnails and previews are supposed to be just hint of what the image is before you open it, so the key for those is to be small, not accurate. JPG is widest supported lossy format so that is best way to generate low filesizes which everyone can see, meanwhile PNG files would be massive and would make the pages load several seconds slower.

There are lossy formats which do support transparency like WebP, however the support is so low that many users would be on page with no images to be seen.

They do, but as JPG does not have transparency support, it simply fills the transparency with first color on palette. This is why images have transparency filled with black instead and some GIF files can have some random background color.

Ah so it IS a formatting thing,
Something to save the secs to see the sex, Right? ╹‿╹)
Understandable to point, while saving a few seconds
"sounds a bit" but I'm guilty of the same thing when it comes skyrim
and lowering the quality for speeds sake.

And like I heard a dood say at some point:
Restraint here would rendered me a hypocrite.
^{or something like that =‿=)}

Notkastar said:
Ah so it IS a formatting thing,
Something to save the secs to see the sex, Right? ╹‿╹)
Understandable to point, while saving a few "seconds"
"sounds a bit" guilty of the same thing when it comes skyrim
and lowering the quality for speeds sake.

And like I heard a dood say at some point:
Restraint here would rendered me a hypocrite.
^{or something like that =‿=)}

If it is sex you are getting to look at then yeah, pretty much. But that's kinda the point I'm trying to make, thumbnails are there so that you know if it's rabbit doing oviposition, machoke fucking wolf or character doing cool action pose. You get the main idea of what you are about to see before you see it or look at the tags.

The main thing is scale. Even if for me the loading time weren't that much, but how would it be for someone with far worse internet connection and/or hundreds of posts on single page?

Also when considering filesize, if it's 5 KB for JPG and 50 KB for PNG, that doesn't sound that huge difference. However now let's say we have 100 000 daily visitors (just pulling this number from my ass), so that would turn out to be 4.5 GB to be downloaded - daily - for one single post thumbnail. So when the scale gets so big that you have thousands of users daily, even mere kilobytes difference in filesize will matter.

Mairo said:
If it is sex you are getting to look at then yeah, pretty much. But that's kinda the point I'm trying to make, thumbnails are there so that you know if it's rabbit doing oviposition, machoke fucking wolf or character doing cool action pose. You get the main idea of what you are about to see before you see it or look at the tags.

The main thing is scale. Even if for me the loading time weren't that much, but how would it be for someone with far worse internet connection and/or hundreds of posts on single page?

Also when considering filesize, if it's 5 KB for JPG and 50 KB for PNG, that doesn't sound that huge difference. However now let's say we have 100 000 daily visitors (just pulling this number from my ass), so that would turn out to be 4.5 GB to be downloaded - daily - for one single post thumbnail. So when the scale gets so big that you have thousands of users daily, even mere kilobytes difference in filesize will matter.

Ah, I get ya, Dood.
It needs to serve the purpose as well as it can!
And that numbers add up, turning ripples into
waves and were one small change can make a world
of Difference! (am I, right? ╹‿╹)

If that's the case, I totally see your point m8, Though it may not
be the prettiest, It serves the purposes well!

So let's-
"Disable Water Reflection and Lower the Vanishing point
so we can explore Skyrim within the year!" ◠‿◠)
^{(Comparatively speaking between Skyrim and 621 and all that, Dood =‿=)}

Also, Those examples made me smile more than they should have.
Was not ready at all for someone to bring up something so "Familiar"
to me.
◠‿╹)~★
Thanks, You made my day with that subtlety, Dood!