Packet Profiler
Java mod listed for Minecraft 1.20. Downloads from the MC Java Mods app on Android.
Profiling packet size transmitted between server and client, debugging loot modifier, and identifying functions in datapacks causing lag
I don't know my version or loader
Discord: https://discord.gg/BCHNhsDMXz
This mod provides 3 functionalities:
Packet profiling
It can record the size and number of all packets transmitted and received at a given side (server or client, depending on where this mod is installed) for a period of time. This allows identifying the cause of large network flow in modpacks, helping to improve server performance.
To profile packet sent or received on server side, run `/profileserver <time in ticks>` command. Result will be stored in `logs/profiler/` folder, separately listing out all packet types sent and received, their count and size.
Loot profiling
It can record all the loot modifiers used for generating loot, showing how each of those loot modifiers modify the loot. It can help to identify why loots are not as expected in a large modpack.
To profile loot, run `/profileloot <time in ticks>` command and do action that can trigger loot table (kill a mob, open a loot chest, run `/loot` command, etc). Report will be printed in your latest.log file or console.
MCFunction Datapack Identification
MCFunction is a vanilla datapack feature that allows running command in datapack. This helps datapacks to develop advanced functionalities but also potentially cause a lot of lag. Some mods use MCFunction in minimal amount to aid mod functionality, such as Twilight Forest and Aether, but if you identifies a lot of lags from MCFunction and couldn't find out who, this feature would help a lot.
You can find out MCFunction lag at `ServerFunctionManager.tick()` and `ServerFunctionManager.execute()` in your server spark report.
To identify what mods have MCFunction datapack, run `/profiledatapack` command. It will list out all namespaces that contain MCFunction files along with the number of MCFunction files in those namespaces. The result will be sorted in descending order.
- Edition: Minecraft Java
- File type: .jar
- Minecraft version listed: 1.20.1
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on CurseForge — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
- Ships as packetprofiler-2.0.3.jar — drop this file into the mods folder
- Download size: 33 KB
- Download link checked 28 Sept 2026 — working
These come from our own check of the pack file, not from the source page.