it's infinite
What's the highest rating that you can get on chess.com?

it's infinite
Not exactly. As long as someone is close enough in rating they can gain rating, but if that person’s rating is too high then no rating is given. Supposing 50% of players in the world continue this way(due to the other 50% always losing rating), 50% of those players can get even higher, then the next 50%, and so on. After a certain point, rating will be maxed out. Now, there are about 130,482,072 players on chess.com. Assuming each player is 500 rating apart(since they can no longer gain or lose rating at that point), i can calculate that the highest rating possible in this variation could be around 65,241,036,000 Elo.

I’m like 99.9 percent sure that in puzzles 65540 is the highest possible Elo because the top 6 people on the puzzle leaderboard are that rating and it doesn’t usually get higher.

I disagree on Infinity, because the highest Chess rating on the Elo Rating system, the highest score you can get is a 2882. So, I would think as Jason543 said, maybe 4000.
Here is Wikipedia’s definition of how to calculate rating: