My usual chapter lengths are around 3,000-4,000 words; around printed-book-length chapters. For the first book I put on Wattpad, I was told this was too long, so I split them up into three parts per chapter.
Due to this, for my second web novel, I decided to reduce the chapter size to about 2,000 words, which is what Wattpad recommends for their website. But when posting it here, I got told Tapas prefers chapters of 1,000 words, so I split them down to two parts each. I don't think I could write a whole chapter in just 1,000 words though.
I suppose a chapter is as long as it needs to be, but it can be a pain when someone complains "the chapter ends abruptly" at the end of Chapter 1 Part 1... (this has happened to me on Wattpad, but not yet on Tapas, admittedly). It's hard to reply, "That's because this isn't the end of the chapter; the chapter is three parts long" without sounding like a colossal bag of feral badgers doused in gravy.