Java NeoForge 1.21.11 JDK 21

Create Your First NeoForge Mod for Minecraft 1.21.11 (2026)

Start NeoForge modding in 2026 for Minecraft 1.21.11: JDK 21, Mod Generator, Gradle import, runClient/runServer, registries, and release testing.

22 min read
Updated May 2026
Intermediate
2026 accuracy note This guide was built from current official documentation checked on May 2026. For preview APIs, always re-check the linked official docs before shipping a public download.

Why NeoForge

NeoForge is a modern Minecraft Java modding platform with official docs for 1.21.11. It is a strong fit for content-heavy mods, registries, server testing, and larger codebases.

Requirements

The official NeoForge getting started docs call for Java 21 and a 64-bit JVM. Use an IDE with Gradle support, such as IntelliJ IDEA or Eclipse, and keep Git available even if you are solo.

Use the Mod Generator

Use the official NeoForge Mod Generator to create a clean project with your mod name, mod id, package name, Minecraft version, and Gradle plugin choice. This avoids a surprising number of broken setup tutorials.

Gradle import

Open the extracted project as a Gradle project and let dependencies download. Edit basic mod metadata in `gradle.properties` before changing the build scripts.

Server testing

Always run a dedicated server test. NeoForge docs specifically call out dedicated server testing because client-only assumptions can crash or misbehave when the mod is loaded server-side.

Example
./gradlew runClient
./gradlew runServer

Build and release

Build with Gradle, then test the output JAR from `build/libs` in a clean NeoForge profile before uploading it to a mod platform.

Example
./gradlew build

Official sources checked

These are the official or primary references used to keep this tutorial current: