Project Zomboid Server Status Checker

Which Port Actually Answers

Project Zomboid dedicated servers listen on UDP 16261 by default, and that is the port that replies to a status query. If you leave the port out, this tool assumes 16261.

Hosting panels frequently assign something else - 16000, 16270, anything free on the box - especially when several servers share one machine. In that case type the full host:port and we will query exactly what you entered instead of overriding it.

One thing worth knowing: a Project Zomboid server also opens a second port for the actual gameplay traffic. A status query only proves that the server process is alive and answering, which is exactly what you want to know before spending time on a connection attempt.

Why Check Project Zomboid Server Status?

Project Zomboid is a game of long commitments. A character that survived four in-game months represents dozens of real hours, and the server holding that save is a single machine somewhere. When it goes down mid-session, everyone connected is thrown out - and if the crash corrupted the save, the community loses that world.

Checking the status first tells you whether the problem is the server or your own connection, which is the difference between waiting calmly and restarting your router for no reason. For admins, it is the fastest way to confirm a player report without logging into the host panel.

Common Reasons a Project Zomboid Server Goes Offline

• Workshop mod update: the single most common cause. A mod updates on Steam, the server no longer matches what clients download, and it refuses connections or fails to start.
• Out of memory: the server runs on Java with a fixed heap. Large maps, many players and heavy mod lists exhaust it, and the process dies.
• Build change: a client update to a new build makes the server version incompatible until it is updated too.
• Corrupted save: a crash during a write can leave the world in a state the server cannot load on the next start.
• Scheduled restart: many hosts restart nightly to reclaim memory. A check during that window shows offline for entirely healthy reasons.
• Firewall or port forwarding: on a self-hosted box, UDP 16261 has to be open inbound. TCP rules alone do nothing here.

Continuous Monitoring for Server Owners

A one-off check answers the question right now. If you run the server, the question you actually care about is whether it stayed up while you were asleep.

With UptyBots you can set up a port monitor on your Project Zomboid server that:

• Queries UDP 16261 from several countries every 1 to 5 minutes.
• Alerts you by email, Telegram or webhook the moment it stops answering.
• Records uptime history, so a nightly crash shows up as a pattern instead of a rumour.
• Gives you a public status badge for your Discord or community page.

Frequently Asked Questions

What is the default Project Zomboid server port?

UDP 16261. If your host assigned a different one, append it to the address with a colon, like example.com:16270.

The server shows offline but I can play on it. Why?

Almost always a port mismatch: you are connecting through the port your host gave you, while the check went to the default. Enter the full host:port and try again.

Does this work for modded servers?

Yes. The query happens at the network level and does not care which mods are loaded. It will, however, tell you when a bad mod update has taken the server down.

Is this checker free?

Yes, free and without signup. For continuous checks with alerts and uptime history, create a free UptyBots account.