Startup Parameter Builder

Select Game

Java Edition server with JVM optimization flags

Preset

Memory Settings

Configure RAM allocation for your server

Minimum RAM (MB)

Initial memory allocation

Maximum RAM (MB)

Maximum memory the server can use

JVM Optimization

Advanced Java Virtual Machine settings

Use Aikar's FlagsRecommended GC optimization flags for Minecraft servers

Garbage Collector

Java garbage collection algorithm

Server Options

Basic server configuration

JAR File Name

Name of your server JAR file

Server Port

Port number for the server

Enable GUIShow server GUI window (disable for headless)

Force World UpgradeForces upgrade of world files on startup

Safe ModeLoad server with only vanilla datapack

Generated Startup Command

java -Xms1024M -Xmx4096M -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

Tip: Save this as start.bat (Windows) or start.sh (Linux/Mac) in your server directory.

About Startup Parameters

Startup parameters control how your game server launches and operates. For Java-based games like Minecraft, JVM flags can significantly impact performance. Aikar's flags are widely recommended for Minecraft servers and provide excellent garbage collection optimization.