[2022] How many players can play on a server?

More than 8 is not technically officially supported, But there is an ingame option to host for as many as 16 players via ingame hosting.

If you have a super tanky top of the line Server PC, you could probably swing as many as 64 by disabling horde nights. Maybe. But I wouldn't recommend it, as it would likely have a lot of issues.

And to note, The maps are at most 10km squared, and even 16 can start feeling very crowded very quickly.

And also to note, every additional player is an additional number of zombies active at one time, but the server has a built in limit (that is adjustable) of 80 by default; So with a default horde night setting of 8 zombies per person, no more than 10 people would have zombies- This also is a problem just when a lot of people are wandering around, if one player has 20 zombies loaded around them, maybe some guy across the map has less than he should or even none. So definitely tune this value to your use case. (I'd suggest a value of no more than 16 per expected player, personally. And to not go over 200 unless you've got a monster rig.)

So...Officially as a moderator, I'd recommend 8-16 tops unless you're extremely confident in your server PC, at which point as much as 32 but no higher.

I’d assume the official supported limit of eight players is with a dedicated server in mind. Since you asked about a player-hosted server, I’d expect the practical limit there to be lower than that if anything, because the host’s machine has to host the game for everyone at the same time it’s processing the game client for one player.

In my experience, trying to locally host more than four players at a time is asking for trouble, even with solid hardware and a central geographic location. But I haven’t tried to test the limit in a long time, and my internet connection was upgraded since then etc. etc., so I don’t have a reliable figure.

If you have a dedicated server, I see little reason not to use it.