
Modrinth · Minecraft mod
Spark Unforged
A backport of the performance profiling mod Spark to 1.12.2
Quick answer
Which Spark Unforged release should I use?
Spark Unforged 1.11.140 targets 1.12.2 with Forge. Installation on the client is optional. Installation on the dedicated server is optional. No extra mods listed for this file.
Where it goes
Is Spark Unforged required on the client, server, or both?
Installation on the client is optional. Installation on the dedicated server is optional.
The source marks this as usable on both the client and server.
What else does Spark Unforged 1.11.140 need?
1.11.140. 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 Spark Unforged without breaking your instance.
Built for Spark Unforged 1.11.140. Pick another file and the loader, install side or required mods may change.
- 01
Stick to this file
Use 1.11.140. It targets 1.12.2 with Forge; 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
Installation on the client is optional. Installation on the dedicated server is optional.
- 04
Pick the file you checked
Use the “Get this file” button beside 1.11.140. It opens that exact file at the source.
About this project
What does Spark Unforged add?

Spark Unforged is a backport of spark to bring updated features to 1.12.2
Spark Unforged is forked from spark and licensed under GNU GPLv3
Original Project: (https://github.com/lucko/spark) (https://www.curseforge.com/minecraft/mc-mods/spark) (https://modrinth.com/mod/spark)
Original License: (https://github.com/lucko/spark/blob/master/LICENSE.txt)
New as of 1.11.1
NOTE: Spark Unforged now relies on Mixin, most packs will already have some mod or another loading Mixin, but if not, you will need to add a mod like MixinBootstrap or Mixin 0.7-0.8 Compatibility to load Mixin.
A newly added feature available in Spark Unforged is Load Profiling.
Load profiling can profile CPU performance and time spent (As well as if you are on a system that can utilize the Async profiler, Memory Allocation) throughout the loading process, with options for profiling specific sections such as coremod, init, postinit, etc. as well as the whole game load and server load process. Load profiling is disabled by default and can be enabled in the config in config/spark/config.json (Config options are written to the file when accessed, so toggling it on and specific options will be available once ran once.) Load profiling will not automatically upload files to the spark viewer server for the sake of sparing upload spam, instead the files when done will be automatically saved to the config/spark/data folder and can be uploaded to and viewed through the spark site.
Whats Spark? Whats Spark Unforged?
Spark is a performance profiling tool that can be used to get highly detailed information on many aspects of your running Minecraft games/servers.
Such tools includes CPU profling, Memory Inspection, Server Health Reporting, and more.
Spark Unforged is a backport of modern Spark to 1.12.2, to bring many newer features such as improved data availability and Async profiling to 1.12.2, as well as some new features such as load profiling.
Isn't there already a Spark for 1.12.2?
While there are versions of Spark on the original Curseforge for 1.12.2, those versions are heavily outdated and missing many new QoL features, and also has missing tools such as Async profiling which is one of the most useful tools for determining performance issues, and the custom new profiling added by Spark Unforged.
Whats the difference from modern Spark?
Spark Unforged has primarily the same functions, commands, features, etc as modern Spark, with a few exceptions:
- Loading profiling, with options for profiling various load states such as coremod, preinit, init, etc. as well as server/world loading.
- Load profiling also works with memory allocation profiling and async profiling.
- Better configuration file, options when accessed will write to the file for easier use by users.
- Extra Server Metadata is disabled (This was for listing datapacks, which don't exist in 1.12.2.)
- Open/Live Profile Viewing is disabled due to limitations of 1.12.2 still being on Java 8.
So how do I use it?
Spark Unforged is nearly identical in function to modern Spark (With the exception of previously mentioned disabled feature) and as such uses the same commands and formatting.
You can find guides on commands, usage, and tips on Spark's Wiki (https://spark.lucko.me/docs)
Commands: (https://spark.lucko.me/docs/Command-Usage)
Usage: (https://spark.lucko.me/docs/Using-the-viewer)
Guides: (https://spark.lucko.me/docs/guides/Finding-lag-spikes)
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Project description from Modrinth.
Pick your setup
Spark Unforged 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
Spark Unforged versions and loaders
1.11.140
spark-unforged-1.11.140-forge.jar
10 Jul 2025
1.11.2
spark-unforged-1.11.2-forge.jar
6 May 2024
1.11.1
spark-unforged-1.11.1-forge.jar
17 Aug 2023
1.11.0
spark-unforged-1.11.0-forge.jar
10 Aug 2023
Looking for an older file? The official Modrinth project page is in Resources.