Server Startup Flags Generator

Generate Aikar's optimized JVM startup flags and Windows / Linux launch scripts for Minecraft servers based on available memory, with the required Java version selected automatically.

Allocated Memory: 8 GBUsually, allocate 1–2 GB less than the server's total memory to leave room for the system; 4–8 GB is enough for a small server.

Server File Name

System

Aikar's Flags (Recommended)Hide GUIRestart After Crash

Java 26.3 servers require Java 25 (as specified in Mojang's official version manifest).Aikar's flags make garbage collection smoother and reduce lag. The high-memory flags are used automatically when memory is ≥ 12 GB.

#!/usr/bin/env bash
cd "$(dirname "$0")"
while true; do
  java -Xms8G -Xmx8G -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1NewSizePercent=30 -XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=8M -XX:G1ReservePercent=20 -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:InitiatingHeapOccupancyPercent=15 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:+PerfDisableSharedMem -XX:MaxTenuringThreshold=1 -Dusing.aikars.flags=https://mcflags.emc.gs -Daikars.new.flags=true -jar server.jar --nogui
  echo "服务器已关闭，10 秒后重启，按 Ctrl+C 取消"
  sleep 10
done

start.sh · 700 characters

Generate Aikar's optimized JVM flags and a startup script based on your server's memory. Note the Java version: 1.17 requires Java 16, 1.18–1.20.4 requires Java 17, and 1.20.5 and later require Java 21.