Model Comparison

Claude Sonnet 4.5 vs Kimi K2 0905

Claude Sonnet 4.5 significantly outperforms across most benchmarks. Kimi K2 0905 is 5.6x cheaper per token.

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Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Claude Sonnet 4.5 outperforms in 1 benchmarks (GPQA), while Kimi K2 0905 is better at 0 benchmarks.

Claude Sonnet 4.5 significantly outperforms across most benchmarks.

Mon Apr 27 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Kimi K2 0905 costs less

For input processing, Claude Sonnet 4.5 ($3.00/1M tokens) is 5.0x more expensive than Kimi K2 0905 ($0.60/1M tokens).

For output processing, Claude Sonnet 4.5 ($15.00/1M tokens) is 6.0x more expensive than Kimi K2 0905 ($2.50/1M tokens).

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

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

Lowest available price from all providers
Mon Apr 27 2026 • llm-stats.com
Anthropic
Claude Sonnet 4.5
Input tokens$3.00
Output tokens$15.00
Best providerAnthropic
Moonshot AI
Kimi K2 0905
Input tokens$0.60
Output tokens$2.50
Best providerNovita
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

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

Anthropic
Claude Sonnet 4.5
Input200,000 tokens
Output64,000 tokens
Moonshot AI
Kimi K2 0905
Input262,144 tokens
Output262,144 tokens
Mon Apr 27 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude Sonnet 4.5 supports multimodal inputs, whereas Kimi K2 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 0905

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Sonnet 4.5

Proprietary

Closed source

Kimi K2 0905

Proprietary

Closed source

Release Timeline

When each model was launched

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

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

Claude Sonnet 4.5

Sep 29, 2025

7 months ago

3w newer
Kimi K2 0905

Sep 5, 2025

7 months ago

Knowledge Cutoff

When training data ends

Claude Sonnet 4.5 has a documented knowledge cutoff of 2025-01-31, while Kimi K2 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 0905's cutoff date.

Claude Sonnet 4.5

Jan 2025

Kimi K2 0905

—

Provider Availability

Claude Sonnet 4.5 is available from Anthropic. Kimi K2 0905 is available from Novita.

Claude Sonnet 4.5

anthropic logo
Anthropic
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M

Kimi K2 0905

novita logo
Novita
Input Price:Input: $0.60/1MOutput Price:Output: $2.50/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
Supports multimodal inputs
Higher GPQA score (83.4% vs 75.8%)
Moonshot AI
Larger context window (262,144 tokens)
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Sonnet 4.5
Moonshot AI
Kimi K2 0905

FAQ

Common questions about Claude Sonnet 4.5 vs Kimi K2 0905

Claude Sonnet 4.5 significantly outperforms across most benchmarks. Claude Sonnet 4.5 is made by Anthropic and Kimi K2 0905 is made by Moonshot AI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.
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 0905 scores HumanEval: 94.5%, MMLU: 90.2%, MATH: 89.1%, MMLU-Pro: 82.5%, GPQA: 75.8%.
Kimi K2 0905 is 5.0x cheaper for input tokens. Claude Sonnet 4.5 costs $3.00/M input and $15.00/M output via anthropic. Kimi K2 0905 costs $0.60/M input and $2.50/M output via novita.
Claude Sonnet 4.5 supports 200K tokens and Kimi K2 0905 supports 262K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include context window (200K vs 262K), input pricing ($3.00 vs $0.60/M), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.
Claude Sonnet 4.5 is developed by Anthropic and Kimi K2 0905 is developed by Moonshot AI.