MoonshotAI: Kimi K2 Thinking

by MoonshotAI

Kimi K2 Thinking is Moonshot AI’s most advanced open reasoning model to date, extending the K2 series into agentic, long-horizon reasoning. Built on the trillion-parameter Mixture-of-Experts (MoE) architecture introduced in Kimi K2, it activates 32 billion parameters per forward pass and supports 256 k-token context windows. The model is optimized for persistent step-by-step thought, dynamic tool invocation, and complex reasoning workflows that span hundreds of turns. It interleaves step-by-step reasoning with tool use, enabling autonomous research, coding, and writing that can persist for hundreds of sequential actions without drift. It sets new open-source benchmarks on HLE, BrowseComp, SWE-Multilingual, and LiveCodeBench, while maintaining stable multi-agent behavior through 200–300 tool calls. Built on a large-scale MoE architecture with MuonClip optimization, it combines strong reasoning depth with high inference efficiency for demanding agentic and analytical tasks.

Avg Score

82.4%

233 answers

Avg Latency

10.2s

13 runs

Pricing

$0.40

input

$1.75

output

per 1M tokens

Context

262K

tokens

Alternatives

Models with similar or better quality but different tradeoffs

Same Quality, Cheaper

Models with similar or better performance at a lower cost per token.

Model	Cost
Google: Gemini 2.0 Flash	-91%
DeepSeek: DeepSeek V3.2	-79%
DeepSeek: DeepSeek V3 0324	-67%
Google: Gemini 2.5 Flash	-25%
Mistral: Mistral Large 3 2512	-21%

Same Quality, Faster

Models with similar or better performance but lower latency.

Model	Latency
Google: Gemini 2.0 Flash	-89%
Google: Gemini 2.5 Flash	-87%
Google: Gemini 3 Flash Preview	-82%
Anthropic: Claude Sonnet 4.5	-67%
OpenAI: GPT-5.2 Chat	-62%

Same Cost, Better

Models at a similar price point with higher benchmark scores.

Model	Score
Google: Gemini 3 Flash Preview	+8%

Other Models from MoonshotAI

Compare performance with other models from the same creator

Model	Score	Latency	Cost/1M
MoonshotAI: Kimi K2 0905	—	—	$1.15
MoonshotAI: Kimi K2 0905	—	—	$1.55
MoonshotAI: Kimi K2 0711	—	—	$0.0000
MoonshotAI: Kimi K2 0711	—	—	$1.45
MoonshotAI: Kimi Dev 72B	—	—	$0.72

Benchmark Performance

How this model performs across different benchmarks

Benchmark	Score	Rank
Math Bench: Addition (1-10)	100.0%	16 / 35
Math Bench: Subtraction (1-10)	100.0%	18 / 35
Math Bench: Multiplication (1-10)	100.0%	20 / 35
Math Bench: Division (1-10)	100.0%	23 / 35
Math Bench: Arithmetic (1-100)	100.0%	20 / 35
Math Bench: Arithmetic (1-1000)	100.0%	2 / 35
Character Frequency Bench	100.0%	4 / 35
Spatial Reasoning: Germany	94.8%	7 / 35
Product Recommendations	88.8%	2 / 36
Karlsruhe Local Knowledge Benchmark	82.8%	12 / 35
Money Boy Cultural Literacy Test	42.9%	13 / 35
German Memelord Bench	23.4%	14 / 35
Karl Lorey knowlege	9.7%	10 / 36

Price vs Performance

Compare cost efficiency across all models

Current model

Other models

X-axis uses log scale for better visualization of price range

Score Over Time

Performance trends across all benchmark runs

Benchmark Activity

Number of benchmark runs over time

Quickstart

Get started with this model using OpenRouter

View on OpenRouter

import { OpenRouter } from "@openrouter/sdk";

const openrouter = new OpenRouter({
  apiKey: "<OPENROUTER_API_KEY>"
});

const completion = await openrouter.chat.completions.create({
  model: "moonshotai/kimi-k2-thinking",
  messages: [
    {
      role: "user",
      content: "Hello!"
    }
  ]
});

console.log(completion.choices[0].message.content);

Get your API key at openrouter.ai/keys