CurseForge · Minecraft mod
Server lag tester
"/lagtest start" lags the server "/lagtest stop" stops the lag it does not decrease fps based on my testing only increases ping
Quick answer
Which Server lag tester release should I use?
Server lag tester Lagtest-1.0.0-Neoforge targets 1.21.1 with NeoForge. The project page does not say whether this file belongs on the client, dedicated server, or both. No extra mods listed for this file.
Where it goes
Is Server lag tester required on the client, server, or both?
The project page does not say whether this file belongs on the client, dedicated server, or both.
The source does not explicitly classify this release as client-only or server-only.
What else does Server lag tester Lagtest-1.0.0-Neoforge need?
Lagtest-1.0.0-Neoforge. Change the file and its required mods may change too.
This file does not list any required mods. Do not add a library just because a different file uses it.
This file does not list any required or optional mods.
Before you install it
Add Server lag tester without breaking your instance.
Built for Server lag tester Lagtest-1.0.0-Neoforge. Pick another file and the loader, install side or required mods may change.
- 01
Stick to this file
Use Lagtest-1.0.0-Neoforge. It targets 1.21.1 with NeoForge; another release may have different loader, side or dependency requirements.
- 02
Bring the mods it needs
This file does not list any required mods. Do not add a library just because a different file uses it.
- 03
Put it on the correct side
The project page does not say whether this file belongs on the client, dedicated server, or both.
- 04
Pick the file you checked
Use the “Get this file” button beside Lagtest-1.0.0-Neoforge. It opens that exact file at the source.
About this project
What does Server lag tester add?
/lagtest start 1-2000000
causes lag
/lagtest status
tells you if there is lag and how much
/lagtest stop
stops the lag
The mod can be used for testing server latency it is not recomended to use more than 2000 because it might make it unplayable. this mod does not decrease your fps it can cause your fps to go up but that's just an unintended effect of the chunks loading slower.
Mod compatibility is untested so it could possibly break other mods so be advised while using this mod with any other mods.
Project description from CurseForge.
Pick your setup
Server lag tester by Minecraft version and loader
Choose the version and loader you play, then open the matching release.
Check the dependencies, then try the file in a copied instance before changing a world you care about.
Recent files
Server lag tester versions and loaders
lagtest-0.0.1-1.21.1 Forge
lagtest-0.0.1-1.21.1.jar
27 Aug 2026
Lagtest-1.0.0-Neoforge
lagtest-1.0.0-Neoforge.jar
27 Aug 2026
Looking for an older file? The official CurseForge project page is in Resources.