Kimi K2 Thinking

The Next Generation Open-Source Reasoning AI Model with Trillion Parameters

1T Parameters
256K Context
Open Source
INT4 Quantization

What is Kimi K2 Thinking

Kimi K2 Thinking Overview

Kimi K2 Thinking is the latest generation open-source reasoning AI model developed by Moonshot AI, officially released in November 2025. As the pinnacle of the Kimi model series, Kimi K2 Thinking is specifically designed for complex reasoning tasks and serves as an intelligent agent with "thinking" capabilities.

The Kimi K2 Thinking model extends the K2 series into long-horizon, agentic reasoning, meaning the model can sustain a multi-step chain-of-thought over very lengthy interactions.

About Moonshot AI

Moonshot AI was founded in 2023 by Yang Zhilin and colleagues, headquartered in Beijing. As one of China's "AI Unicorn" companies, it focuses on large language model development.

The Kimi series evolution: Initial release (late 2023) โ†’ K1.5 (early 2025) โ†’ K2 (July 2025) โ†’ K2-Instruct (September 2025) โ†’ Kimi K2 Thinking (November 2025).

Kimi K2 Thinking Technical Architecture

MoE Architecture

1 trillion total parameters, 32 billion active per inference

Training Data

15.5 trillion tokens of high-quality data

Optimization

Custom Muon optimizer for stable training

Features of Kimi K2 Thinking

Trillion-Parameter Scale

Sparse MoE architecture with 1T total parameters and 32B activated per inference for optimal performance

256K Context Window

Process up to 200,000+ words in a single context, far exceeding traditional LLM capabilities

INT4 Quantization

Native 4-bit quantization doubles inference speed without performance loss

Open Source License

Fully open weights and code under modified open-source license for research and commercial use

Tool Calling Support

Invoke external tools and functions during reasoning process for enhanced capabilities

Advanced Reasoning

Multi-step chain-of-thought reasoning for complex problem-solving tasks

Kimi K2 Thinking Key Advantages

Lossless Performance

Maintains complete model performance at INT4 precision with quantization-aware training

Memory Optimization

Significantly reduces deployment memory requirements for cost-effective scaling

Training Stability

Zero instabilities during pre-training with custom Muon optimizer

Long Document Processing

Complete processing of technical documents and entire codebases

Kimi K2 Thinking Comparison

Performance Benchmarks

BenchmarkKimi K2 ThinkingGPT-4Claude-3
Math Reasoning (GSM8K)94.2%92.0%90.1%
Code Generation (HumanEval)89.7%87.3%85.9%
Logical Reasoning (HellaSwag)96.1%95.3%94.8%
Chinese Understanding (C-Eval)91.8%86.4%84.2%

Open Source Model Comparison

FeatureKimi K2 ThinkingLlama 3.1 405BQwen2.5 72B
Parameter Scale1T (32B active)405B72B
Context Length256K128K32K
Open Source LicenseModified Open SourceLlama LicenseApache 2.0
Chinese CapabilityExcellentGoodExcellent
Reasoning AbilityExcellentGoodGood

How to Use Kimi K2 Thinking

01

Installation

Download Kimi K2 Thinking model weights from official sources

pip install transformers torch
02

Configuration

Set up your environment with required hardware specifications

  • 80GB+ GPU Memory
  • 256GB+ System RAM
  • 2TB+ SSD Storage
03

Deployment

Deploy Kimi K2 Thinking using your preferred method

  • Docker Container
  • Kubernetes Cluster
  • Direct Installation

Quick Start Code Example

# Load Kimi K2 Thinking model
from transformers import AutoModelForCausalLM, AutoTokenizer

model = AutoModelForCausalLM.from_pretrained("moonshot-ai/kimi-k2-thinking")
tokenizer = AutoTokenizer.from_pretrained("moonshot-ai/kimi-k2-thinking")

# Inference example
inputs = tokenizer("Analyze this complex problem:", return_tensors="pt")
outputs = model.generate(**inputs, max_length=1000)
response = tokenizer.decode(outputs[0], skip_special_tokens=True)

print(response)

Use Cases for Kimi K2 Thinking

Enterprise Applications

  • Intelligent customer service systems
  • Code development assistants
  • Document processing automation
  • Contract review and analysis

Research & Education

  • Academic research assistance
  • Literature review generation
  • Educational content creation
  • Data analysis support

Frequently Asked Questions

What is Kimi K2 Thinking?

Kimi K2 Thinking is a trillion-parameter open-source reasoning AI model developed by Moonshot AI, designed for complex reasoning tasks with 256K token context window and tool calling capabilities. It represents the most advanced version in the Kimi model series.

What are the hardware requirements for Kimi K2 Thinking?

Minimum requirements include 80GB GPU memory (such as A100 or H100), 256GB system memory, and 2TB SSD storage space. For optimal performance, H100 or newer GPUs are recommended.

How much does Kimi K2 Thinking cost?

As an open-source model, Kimi K2 Thinking itself is free. Users only need to bear hardware deployment costs ($50,000-200,000 initial investment) and operating costs ($1,000-5,000/month). Commercial use must comply with open-source license terms.

What makes Kimi K2 Thinking different from other models?

Kimi K2 Thinking features a unique combination of trillion-parameter MoE architecture, 256K context window, native INT4 quantization, and advanced reasoning capabilities. It excels in Chinese processing and long-horizon reasoning tasks compared to other models.

Which programming languages does Kimi K2 Thinking support?

Kimi K2 Thinking supports mainstream programming languages including Python, JavaScript, Java, C++, Go, Rust, and more, with excellent performance in code generation and understanding tasks.

How fast is Kimi K2 Thinking inference speed?

With INT4 quantization, Kimi K2 Thinking achieves 100% speed improvement compared to FP16 inference, processing thousands of tokens per second on A100 GPUs without performance degradation.

Can Kimi K2 Thinking be deployed on multiple GPUs?

Yes, Kimi K2 Thinking supports model parallelism and tensor parallelism, allowing deployment across multiple GPUs for effective compute resource utilization and improved performance.

What industries can benefit from Kimi K2 Thinking?

Kimi K2 Thinking is particularly suitable for finance, legal, medical, education, and research industries requiring complex reasoning. It excels in document analysis, decision support, and knowledge Q&A scenarios.

How does Kimi K2 Thinking ensure data privacy?

Kimi K2 Thinking supports local deployment, keeping data within enterprise networks. It provides data encryption, access control, and other privacy protection features, complying with major privacy regulations.

Where can I access Kimi K2 Thinking resources?

Kimi K2 Thinking resources are available through official channels including GitHub repositories, Hugging Face Model Hub, technical documentation, and community forums. Visit the official Moonshot AI website for complete access information.

Pricing Plans

Choose the perfect plan for your AI needs

Most Popular

Kimi-K2-Thinking Starter

$9/month

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  • 1M tokens free trial

Kimi-K2-Thinking Ultra

$49/month

๐Ÿš€ Best value for heavy users ยท 70M tokens

  • 70M tokens/month
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  • Annual discount: $399/year (Save $189)
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