I call it a manga in webcomic/webtoon format. Manga is just how japanese comics are called, no matter the format. Besides we call the korean and chinese comics in vertical strip format manhwa and manhua event though they used to have the same paging style that most manga still have and there are manhwa and manhua still some in that style. I see no difference between those three cases.

One point of contention I have with people claiming that full color long strip comics of Japanese origin designed for online viewing aren't manga is that I've seen on multiple occasions mangas that started out in traditional black and white page format, but were later converted to webtoon format.

(This isn't to say they're good of course, the ones I've seen this done to have been universally terrible, but they were honestly terrible to begin with, and terrible manga is still manga.)

Does it stop being a manga once that happens even though it's still the exact same comic? If I read the first 5 chapters in traditional format and then the official translation comes out only in webtoon format and I read the rest from there, do I lose the right to say I was reading a manga? What do I call it if I'm talking about the series and story as a whole?

Also, anyone who thinks that it's fine to just call them all webtoons as if there's no difference must not read a combination of manhwa, manga, and manhua, because they are wildly different in tropes, average quality, and art.

This is painting them with a broad brush, and of course there are always exceptions, but just like western comics generally look and feel quite different from manga, manhwa and manhua also have their own distinct vibes and tropes. If you're familiar with the three, you can usually pretty easily tell which one it is you're reading, even if it's in webtoon format.

Quote from Ruruskadoo

One point of contention I have with people claiming that full color long strip comics of Japanese origin designed for online viewing aren't manga is that I've seen on multiple occasions mangas that started out in traditional black and white page format, but were later converted to webtoon format.

...but you have no issues, with how full colour strips, have existed long before the internet? (though admittedly not long strips, I don't think ...which I despise, but that's neither here nor there)
I'm pretty sure they've been around, for as long as manga has existed. Also full colour manga, that isn't in strip-format, of course. (which as, no doubt, existed for about as long as non-strip manga has. Strips probably being the oldest form ... actually, comics that are just one single panel, is probably older. That's certainly the oldest type, in the West)

but just like western comics generally look and feel quite different from manga

...and, within Western comics, American ones look and feel different to French ones, and so on.

But yeah, I don't get people who conflate manhwa and/or manhua, with manga. I can generally instantly tell if a comic is Chinese/Korean, rather than Japanese. They have a different style.

If you're reading...

I'm not. I hate these T^T and I find them unbearable to read...

... but I would call it a webcomic, I guess. It's tragic when a manga I actually LIKE gets converted to webcomic format, because I genuinely can't enjoy reading them anymore, so I just drop them and mourn..

...Hop!

I just wonder how Long-strip can be printed in newspaper without converting it into "x pages"? (Bcs longstrip means whole chapter is one strip/page with height exceeding 10/20/40x normal page, you can compare it to comedy's ancient scrolls unrolling to the floor and big stairs/one room further xd)

Yeah okay, so long strips are a new thing, and (AFAIK) only exist digitally, meant for the internet.
I messed up there, and thanks for correcting me.
Still, the only new aspect, about them, is their absurd length, and (as I've said) manga come in various different formats
...and the rest of what I've said, still stands.
As I've said:
Manga=Japanese comic, and webcomic=comic that is published online (though some later also get physical releases ...whilst still remaining online), with neither term having anything to do with format ...and "webtoon" is just plain wrong.

Personally I like longstrip but yeah it's pixel height is absurdly, how to have on disc any longstrip chapter in image format without cutting someones head? 🤣

Edit: Imo Manga is manga xd Webtoon/longstrip it's just second word to name the type, like instead of "webcomic" it's even better to say "webmanga" and "longstrip webmanga" (as "comic"/horizontal/printable-in-old-standard-format for me is default type) as many people who see difference between asian and non-asian (eg see "anime" as "asian animation" not just "animation") often read word "comic" as "non-asian comic" rather than as "it's type of media, not about orgin"

Quote from Nyxsha

(eg see "anime" as "asian animation" not just "animation")

Much as with "manga", I don't see any sane/rational/reasonable reason, to define anime as "East Asian animation". (which I think is what you actually meant. Surely, you're not including countries like Iranian, Kyrgyzstan, Indian, Nepal, Uzbekistan ...or, indeed, Russia [most of its population is in Europe, but...]), rather than "Japanese animation". (so never Chinese or Korean ...nor "manga style" Western stuff, like Avatar)
(as for meaning "animation", any and all, regardless or origin, as is the Japanese meaning... That makes no sense. That's called "animation". Why randomly/arbitrarily use a Japanese word, when using English? This obviously also applies to "manga", meaning "comics")
...but that's very much off-topic, of course, so I won't go into any further details, or comment further on it.