chess.com stops it at 500 if u try to view it, if u wanna see proof for 544 click on this link chess.com/member/rock303 , click "full stats" for bullet, click "797 games", select "unrated" on the right, type in "mangomankey" for opponent, then click "search".
a world record for most moves in a bullet chess game..?

i THINK my keyboard is broken I can do this when I press shift with numbers
ĂÂÊỘ̣̣̀̀̉̃̀̉̃́̉̃́̃́̃́̃́́́Đ̣́̃̀̉̀̉ỒÊÔẦÔỀÔÊỖ̀̉̃́́̃̉̀ÔÔÊÔÊÔÊÔÔÊỒỘ̀̉̉̉̃́̃̉́̃̉̃́̉̃́̃́̉̉̉̉̃́̃́_̣̣́_

I have no idea
It even goes on other posts
I tried it on word it doesn't work but it works on here
̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉̉
So maybe the limit is around 2,200 moves. Go spend a few hours and do it.
I found this old thread looking for this very topic. After reading it, I googled it and there is a post on Quora that explains it to be 6,350 moves maximum if using the 50 move rule. Can you see anything wrong with the reasoning or math in the post?
https://www.quora.com/Can-a-chess-game-be-neverending
https://www.chess.com/live/game/4322938763 544
For me, they're all just 500