Fixing Lag on Your Terraria Server

Terraria server problems fall into three categories: crashes, mod performance issues, and network lag. Each has different symptoms and different fixes. Find the section that matches what you’re seeing.

Server Crashes (Out of Memory)

If your server shuts down or restarts unexpectedly, it’s likely running out of RAM. This is a crash, not lag - the server stops rather than slowing down.

Check your RAM usage on the Console page in the Game Panel. If you’re consistently at 90%+ before a crash, you need more memory. See our RAM guide for sizing by mod combination, and upgrade your plan if needed.

For more on diagnosing OOM crashes, see Out of Memory Crashes.

Mod Performance Issues (tModLoader)

If your server lags and you’re running tModLoader, the mods are the most likely cause. These fixes apply specifically to modded servers.

Check for Mod Conflicts

Open the Console and look for repeating error messages. Mod conflicts and version mismatches cause continuous error logging that degrades performance over time.

Signs of a mod conflict:

• Error messages that repeat every few seconds in the console
• Lag that started after adding a specific mod
• Crashes when entering specific biomes or triggering specific events

Remove the most recently added mod and test again. If the lag stops, you’ve found the problem. Also check that all your mods match your tModLoader version - outdated mods on newer tModLoader are a frequent source of errors.

Reduce Active Mod Count

Even small mods add per-tick processing overhead. If you’re running 30+ mods, disable any your group isn’t actively using.

Edit enabled.json through the File Manager. Remove mods you don’t need, then restart the server.

Restart Regularly

tModLoader servers accumulate memory overhead during long sessions. If lag builds up over hours of play but a restart fixes it, schedule a daily restart during your group’s off-hours.

1. Go to the Console page
2. Click Stop to save and shut down
3. Wait for the server to fully stop
4. Click Start

Network Lag (Desync and Rubber-Banding)

If enemies teleport, blocks reappear after you break them, or damage registers late, that’s network latency - not server performance. This affects specific players based on their connection, not all players equally.

Player-Side Fixes

If only some players experience lag while others play fine, the problem is on their end. The most common fixes:

• Connect via direct IP instead of Steam relay. Your server’s IP and port are on the Console page. Direct connections have lower latency.
• Use Ethernet instead of WiFi. WiFi adds latency variance that causes NPC rubber-banding.
• Fix NPC desync. Set MultiplayerNPCSmoothness to 0 in the local Terraria config.json file. This fixes the visual snapping of enemies between positions.
• Close bandwidth-heavy apps. Discord screen sharing, streaming, and cloud sync all compete for network.

Change Server Location

If all players experience consistent desync, the server may be too far from your group geographically. Check your ping to the server - if it’s above 100ms for most players, a closer location will help.

See our server location changes guide for available locations and how to request a migration.

Quick Diagnosis

For a deeper dive into all lag causes including client-side settings and optimization, see our full Terraria lag guide.