Do you regularly see the message "Can't keep up! Is the server overloaded?" in your Minecraft server console? In this article, we explain what this means and how to fix it.

What does this message mean?

Minecraft tries to perform a "tick" (game update) 20 times per second. If this cannot be done in time, this message appears. This is called tick lag, and causes a slow, stuttering server for players.

Common causes

• Too little allocated RAM, or too much (too much RAM can cause garbage collection pauses).
• Heavy plugins or mods, for example plugins with a lot of entity tracking or redstone-heavy circuits.
• Too many entities (mobs, items, redstone clocks) in a small area.
• A very large world with many loaded chunks.
• A slow or overloaded disk (I/O).

How do you fix this?

1. Check memory usage in the Game Panel. Adjust your allocated RAM if needed, more is not always better.
2. Create a TIMINGS or Spark report to see which plugin, mod, or task is taking the most time. See our articles on TIMINGS reports and the Spark plugin.
3. Remove or replace heavy plugins/mods that turn out to be the cause.
4. Reduce the number of mobs/entities, for example via a mob limit plugin or by adjusting spawn-limits.
5. Use Paper instead of Spigot or Vanilla, Paper has many extra optimizations specifically aimed at this type of lag.

Note: A single "Can't keep up!" message is often not a problem. If this message occurs structurally and often, further investigation is needed.

Still stuck? Feel free to reach out via Discord or create a support ticket.