Model Comparison

Claude Sonnet 4.5 vs Kimi K2-Thinking-0905

Kimi K2-Thinking-0905 shows notably better performance in the majority of benchmarks. Kimi K2-Thinking-0905 is 7.0x cheaper per token.

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Performance Benchmarks

Comparative analysis across standard metrics

3 benchmarks

Claude Sonnet 4.5 outperforms in 1 benchmarks (Terminal-Bench), while Kimi K2-Thinking-0905 is better at 2 benchmarks (AIME 2025, GPQA).

Kimi K2-Thinking-0905 shows notably better performance in the majority of benchmarks.

Wed May 06 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Kimi K2-Thinking-0905 costs less

For input processing, Claude Sonnet 4.5 ($3.00/1M tokens) is 6.4x more expensive than Kimi K2-Thinking-0905 ($0.47/1M tokens).

For output processing, Claude Sonnet 4.5 ($15.00/1M tokens) is 7.5x more expensive than Kimi K2-Thinking-0905 ($2.00/1M tokens).

In conclusion, Claude Sonnet 4.5 is more expensive than Kimi K2-Thinking-0905.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers

Wed May 06 2026 • llm-stats.com

Claude Sonnet 4.5

Input tokens$3.00

Output tokens$15.00

Best providerAnthropic

Kimi K2-Thinking-0905

Input tokens$0.47

Output tokens$2.00

Best providerDeepinfra

Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Kimi K2-Thinking-0905 accepts 262,144 input tokens compared to Claude Sonnet 4.5's 200,000 tokens. Kimi K2-Thinking-0905 can generate longer responses up to 262,144 tokens, while Claude Sonnet 4.5 is limited to 64,000 tokens.

Claude Sonnet 4.5

Input200,000 tokens

Output64,000 tokens

Kimi K2-Thinking-0905

Input262,144 tokens

Output262,144 tokens

Wed May 06 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude Sonnet 4.5 supports multimodal inputs, whereas Kimi K2-Thinking-0905 does not.

Claude Sonnet 4.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Sonnet 4.5

Text

Images

Audio

Video

Kimi K2-Thinking-0905

Text

Images

Audio

Video

License

Usage and distribution terms

Claude Sonnet 4.5 is licensed under a proprietary license, while Kimi K2-Thinking-0905 uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

Claude Sonnet 4.5

Proprietary

Closed source

Kimi K2-Thinking-0905

MIT

Open weights

Release Timeline

When each model was launched

Claude Sonnet 4.5 was released on 2025-09-29, while Kimi K2-Thinking-0905 was released on 2025-09-05.

Claude Sonnet 4.5 is 1 month newer than Kimi K2-Thinking-0905.

Claude Sonnet 4.5

Sep 29, 2025

7 months ago

3w newer

Kimi K2-Thinking-0905

Sep 5, 2025

8 months ago

Knowledge Cutoff

When training data ends

Claude Sonnet 4.5 has a documented knowledge cutoff of 2025-01-31, while Kimi K2-Thinking-0905's cutoff date is not specified.

We can confirm Claude Sonnet 4.5's training data extends to 2025-01-31, but cannot make a direct comparison without Kimi K2-Thinking-0905's cutoff date.

Claude Sonnet 4.5

Jan 2025

Kimi K2-Thinking-0905

—

Provider Availability

Claude Sonnet 4.5 is available from Anthropic. Kimi K2-Thinking-0905 is available from DeepInfra, Novita, Fireworks.

Claude Sonnet 4.5

Anthropic

Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M

Kimi K2-Thinking-0905

Deepinfra

Input Price:Input: $0.47/1MOutput Price:Output: $2.00/1M

Novita

Input Price:Input: $0.48/1MOutput Price:Output: $2.00/1M

Fireworks

Input Price:Input: $0.60/1MOutput Price:Output: $2.50/1M

* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

Claude Sonnet 4.5

View details

Anthropic

Supports multimodal inputs

Higher Terminal-Bench score (50.0% vs 47.1%)

Kimi K2-Thinking-0905

View details

Moonshot AI

Larger context window (262,144 tokens)

Less expensive input tokens

Less expensive output tokens

Has open weights

Higher AIME 2025 score (100.0% vs 87.0%)

Higher GPQA score (84.5% vs 83.4%)

Detailed Comparison

AI Model Comparison Table
Feature	Claude Sonnet 4.5	Kimi K2-Thinking-0905

FAQ

Common questions about Claude Sonnet 4.5 vs Kimi K2-Thinking-0905.

Which is better, Claude Sonnet 4.5 or Kimi K2-Thinking-0905?

Kimi K2-Thinking-0905 shows notably better performance in the majority of benchmarks. Claude Sonnet 4.5 is made by Anthropic and Kimi K2-Thinking-0905 is made by Moonshot AI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Sonnet 4.5 compare to Kimi K2-Thinking-0905 in benchmarks?

Claude Sonnet 4.5 scores MMMLU: 89.1%, AIME 2025: 87.0%, TAU-bench Retail: 86.2%, GPQA: 83.4%, MMMUval: 77.8%. Kimi K2-Thinking-0905 scores AIME 2025: 100.0%, HMMT 2025: 97.5%, MMLU-Redux: 94.4%, FRAMES: 87.0%, MMLU-Pro: 84.6%.

Is Claude Sonnet 4.5 cheaper than Kimi K2-Thinking-0905?

Kimi K2-Thinking-0905 is 6.4x cheaper for input tokens. Claude Sonnet 4.5 costs $3.00/M input and $15.00/M output via anthropic. Kimi K2-Thinking-0905 costs $0.47/M input and $2.00/M output via deepinfra.

What are the context window sizes for Claude Sonnet 4.5 and Kimi K2-Thinking-0905?

Claude Sonnet 4.5 supports 200K tokens and Kimi K2-Thinking-0905 supports 262K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Sonnet 4.5 and Kimi K2-Thinking-0905?

Key differences include context window (200K vs 262K), input pricing ($3.00 vs $0.47/M), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Sonnet 4.5 and Kimi K2-Thinking-0905?

Claude Sonnet 4.5 is developed by Anthropic and Kimi K2-Thinking-0905 is developed by Moonshot AI.