LongCat Flash

Meituan's first open-source large language model with 560B parameters and cutting-edge MoE architecture, achieving over 100 tokens/second inference speed

LongCat Flash represents a breakthrough in open-source artificial intelligence, combining massive scale with unprecedented efficiency. This cutting-edge model demonstrates that open-source AI can compete with proprietary systems while offering superior cost-effectiveness and accessibility.

What makes LongCat Flash truly special is its revolutionary MoE architecture that dynamically activates 18.6B-31.3B parameters per token, maximizing efficiency while maintaining exceptional performance. The LongCat Flash model sets new benchmarks for inference speed and cost efficiency in the open-source AI ecosystem.

Whether you're a developer building AI applications or a business seeking to integrate advanced language capabilities, LongCat Flash provides the perfect balance of power, efficiency, and accessibility that the market has been waiting for.

Experience LongCat Flash

Try the power of LongCat Flash firsthand. This demonstration showcases the model's capabilities in understanding context, generating coherent responses, and handling complex queries across various domains.

Why Choose LongCat Flash?

LongCat Flash stands out in the crowded field of large language models by offering unprecedented combination of scale, speed, and efficiency. Discover why developers and enterprises are choosing LongCat Flash for their AI applications.

Ultra-Fast Speed

Over 100 tokens/second inference speed with minimal first-token latency for smooth interaction

  • • Real-time response capabilities
  • • Optimized for conversational AI
  • • Enhanced user experience

Cost-Optimized

Inference cost as low as $0.7 per million output tokens, offering exceptional value

  • • 70% cost reduction vs competitors
  • • Scalable deployment options
  • • Enterprise-ready economics

Open Source

Fully open source, supporting research and commercial use, available on Hugging Face and GitHub

  • • Apache 2.0 license
  • • Active community support
  • • Transparent development

Advanced Agentic Capabilities

LongCat Flash is specifically designed for agentic tasks, excelling in tool use, multi-step reasoning, and complex environment interaction. The model demonstrates superior performance in agentic benchmarks.

Multi-Agent Framework

LongCat Flash utilizes a sophisticated multi-agent synthetic data framework that generates high-difficulty, high-quality training samples. This approach enables the model to handle complex reasoning tasks with exceptional accuracy.

  • • Advanced tool usage and integration
  • • Multi-step reasoning capabilities
  • • Complex environment interaction

Benchmark Performance

LongCat Flash excels in specialized agentic benchmarks, outperforming other open-source models in scenarios requiring sophisticated decision-making and problem-solving abilities.

  • • Superior performance on τ²-Bench
  • • Excellent results on VitaBench
  • • Leading agentic scenario capabilities

Technical Innovation

LongCat Flash's technical excellence stems from groundbreaking innovations in model architecture and training methodologies. These advances enable unprecedented efficiency and performance in open-source AI.

Revolutionary MoE Architecture

LongCat Flash employs a cutting-edge Mixture-of-Experts (MoE) architecture with 560B total parameters, dynamically activating 18.6B-31.3B parameters per token (average ~27B). This innovative approach maximizes efficiency while maintaining exceptional performance.

The LongCat Flash architecture represents a significant leap forward in large language model design. By utilizing dynamic expert activation, LongCat Flash achieves remarkable efficiency without compromising on quality or capabilities.

Key Innovations:

  • Zero-computation Experts: Intelligently bypasses unnecessary computation for simple tokens, optimizing resource utilization
  • Shortcut-connected MoE: Reorders computation and communication steps, enabling overlapping of dense layer calculations and MoE layer communication
  • Dynamic Resource Allocation: Adapts computational resources based on token complexity, ensuring optimal performance

The architecture supports single-batch overlap (SBO) for low-latency, high-throughput inference, making LongCat Flash ideal for real-time applications.

Advanced Training Methodology

LongCat Flash's training process represents a significant advancement in large-scale model preparation, utilizing sophisticated techniques developed through extensive research and experimentation.

Training Highlights:

  • Massive Dataset: Trained on over 200 trillion tokens across diverse domains and languages
  • Multi-stage Approach: Progressive training focusing on reasoning, coding, and agentic capabilities
  • Hyperparameter Transfer: Optimal configurations discovered on smaller models and scaled using theoretical alignment

The training process incorporates a comprehensive stability suite including routing, activation, and optimizer controls to ensure robust training across thousands of accelerators.

Real-World Applications

LongCat Flash's versatility makes it suitable for a wide range of applications across industries. From customer service to enterprise decision-making, discover how organizations are leveraging this powerful AI technology.

🤖

Customer Service

Intelligent support systems

  • • 24/7 automated support
  • • Multi-language handling
  • • Sentiment analysis
💻

Code Generation

Development assistance

  • • Code completion
  • • Bug detection
  • • Documentation
📊

Data Analysis

Business intelligence

  • • Trend analysis
  • • Report generation
  • • Predictive modeling
🎯

Smart Decision

Strategic planning

  • • Risk assessment
  • • Market analysis
  • • Optimization

Performance Excellence

LongCat Flash delivers exceptional performance metrics that rival and often exceed proprietary models. Our rigorous testing and optimization ensure consistent, reliable results across diverse applications.

The performance achievements of LongCat Flash demonstrate that open-source models can compete with and even surpass proprietary alternatives. This breakthrough performance makes LongCat Flash the ideal choice for enterprises seeking cutting-edge AI capabilities without the vendor lock-in.

100+

Tokens/Second

Industry-leading inference speed for real-time applications

$0.7

Cost per 1M Tokens

Unbeatable cost efficiency for large-scale deployments

98.5%

Uptime

Reliable performance with automatic fault recovery

560B

Parameters

Massive scale with efficient MoE architecture

Get Started with LongCat Flash

Ready to harness the power of LongCat Flash? Access comprehensive resources including model downloads, documentation, and community support to accelerate your AI development journey.

Access LongCat Flash

Model Repository

Download pre-trained models and fine-tuned versions for various applications.

Source Code

Explore the implementation, contribute to development, and customize for your needs.

Interactive Demo

Experience LongCat Flash capabilities directly through your web browser.