Minecraft Stress Testing Tool

A comprehensive load testing tool for Minecraft servers using both UDP and TCP protocols. Built with asyncio for high performance and real-time statistics.

⚠️ Legal Warning

This tool is intended ONLY for testing your own Minecraft servers!

Using this tool against servers you don't own is ILLEGAL and may result in:

• Criminal charges
• Civil lawsuits
• IP bans
• Loss of internet service

By using this tool, you acknowledge that you:

• Own or have explicit permission to test the target server
• Understand the potential impact on server performance
• Accept full responsibility for any consequences

Features

Attack Types

UDP Attacks

• Standard UDP Spam: Sends random data packets
• UDP Handshake Flood: Floods with malformed handshake packets
• UDP Query Flood: Floods with query packets

TCP Attacks

• TCP Connect Flood: Exhausts server connection slots
• TCP Status Ping: Simulates player joins for status queries
• TCP True Login: Full login simulation with protocol compliance

Advanced Features

• Asyncio-based: High-performance concurrent connections
• Real-time Statistics: Live monitoring during attacks
• YAML Configuration: Configurable via external files
• Comprehensive Logging: File and console logging
• IP Validation: Built-in IP address validation
• Protocol Compliance: Accurate Minecraft protocol implementation (1.21.1)

Project Structure

stresser/
├── main.py              Entry point, CLI, interactive mode
├── config.yaml          Default configuration
├── requirements.txt     Python dependencies
├── test.py              Quick smoke test
├── README.md
├── .gitignore
├── .gitattributes
└── src/
    ├── __init__.py
    ├── attacks.py       Attack engine (UDP/TCP workers, stats)
    ├── config.py        YAML config loading & validation
    ├── logger.py        File + console logging setup
    ├── protocol.py      Minecraft 1.21.1 protocol (packets, handshake)
    └── utils.py         Helpers (banner, colors, random data)

Installation

Requirements

• Python 3.10+
• Linux/Windows/macOS

Dependencies

pip install -r requirements.txt

Required packages:

• colorama>=0.4.6 - Colored terminal output
• pyyaml>=6.0 - YAML configuration support

Usage

Interactive Mode

python main.py

Configuration Mode

python main.py --config [config_file.yaml]

Default config file: config.yaml

Configuration

Create a config.yaml file:

attack:
  protocol: "tcp"
  method: "connect"
  duration: 30
  threads: 100
  packet_size: 1024
  rate_delay: 0.01

target:
  ip: "127.0.0.1"
  port: 25565

logging:
  enabled: true
  file: "stresser.log"
  level: "INFO"

limits:
  max_threads: 1000
  max_duration: 300
  max_packet_size: 65500
  min_threads: 1
  min_duration: 1
  min_packet_size: 1

Configuration Reference

Key	Values	Description
attack.protocol	tcp, udp	Network protocol
attack.method	connect, join, login (TCP) / spam, handshake, query (UDP)	Attack method
attack.rate_delay	float (seconds)	Delay between sends (lower = more aggressive)
attack.packet_size	1–65500	UDP payload size
logging.level	DEBUG, INFO, WARNING, ERROR	Log verbosity

Attack Methods Explained

UDP Methods

Standard UDP Spam

• Sends random data packets to the server
• Tests UDP handling capacity
• Can overwhelm network interfaces

UDP Handshake Flood

• Sends malformed Minecraft handshake packets
• Tests protocol parsing robustness
• May cause server-side processing overhead

UDP Query Flood

• Floods with legacy query packets (0xFE 0x01)
• Tests query handling performance
• Useful for servers with query enabled

TCP Methods

TCP Connect Flood

• Attempts to establish TCP connections
• Exhausts available connection slots
• Tests connection handling limits

TCP Status Ping

• Performs full handshake + status request
• Simulates legitimate player joins
• Tests server status query performance

TCP True Login

• Complete login sequence with username generation
• Tests authentication and login handling
• Most resource-intensive method

Output and Statistics

Real-time Stats

During attack execution, you'll see:

[📊] Elapsed: 15.2s | Sent: 15420 | Success: 15234 | Errors: 186 | Timeouts: 0

Final Results

--- Attack Results ---
[+] Packets/Connections Sent: 15420
[+] Successful: 15234
[!] Connection timeouts: 0
[❌] Connection refused: 186
[!] Errors: 0
[✅] Total operations: 15420

Logging

Logs are written to stresser.log by default with format:

2026-03-06 14:30:25 - INFO - Attack started: TCP connect on 127.0.0.1:25565
2026-03-06 14:30:55 - INFO - Attack completed successfully

Log levels: DEBUG, INFO, WARNING, ERROR

Safety Features

• IP Validation: Ensures valid IP addresses
• Parameter Limits: Prevents excessive resource usage
• Timeout Handling: Prevents hanging connections
• Error Recovery: Continues operation despite individual failures
• Resource Management: Proper socket cleanup

Performance Considerations

• Thread Limits: Maximum 1000 concurrent operations
• Duration Limits: Maximum 300 seconds per attack
• Packet Size Limits: 1-65500 bytes for UDP
• Rate Limiting: Built-in delays prevent overwhelming local system

Protocol Implementation

Minecraft Protocol Version

• Supports Minecraft 1.21.1 (protocol version 767)
• Offline UUID generation for cracked servers
• Proper VarInt encoding/decoding
• Handshake packet construction

TCP Handshake Flow

1. Establish TCP connection
2. Send handshake packet with protocol version
3. Send login start packet (for login attacks)
4. Send status request (for status attacks)
5. Read server response

Troubleshooting

Common Issues

"Invalid IP address"

• Ensure the target IP is valid IPv4 or IPv6 format
• Check for typos in IP address

"Connection refused"

• Server may not be running
• Firewall blocking connections
• Wrong port number

"Timeout errors"

• Network latency too high
• Server overloaded
• Firewall blocking responses

"Permission denied"

• May need administrator privileges for raw sockets
• Check firewall settings

Performance Tuning

• Reduce thread count if local system is overwhelmed
• Increase timeouts for high-latency networks
• Use smaller packet sizes for UDP attacks
• Monitor system resources during testing

License

MIT — see LICENSE.