The AI arena is free today

Open Superagent

Claude Sonnet 4 vs Kimi K2 0905

Claude Sonnet 4 and Kimi K2 0905 are closely matched at 24.3 and 21.8 on the LLM Stats Score. Kimi K2 0905 is 5.6x cheaper per token.

Anthropic · Moonshot AI · Updated for 2026

Which is better?

Claude Sonnet 4 and Kimi K2 0905 are closely matched on the overall LLM Stats Score at 24.3 and 21.8.

In the 1 individual benchmarks reported for both models, Kimi K2 0905 wins 1; this is a narrower head-to-head signal than the composite indexes.

On price, Kimi K2 0905 is roughly 5.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Kimi K2 0905 also accepts a larger context window (262,144 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Sonnet 4

  • you want predictable pricing at $3.00/M input and $15.00/M output

Choose Kimi K2 0905

  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results
  • cost matters — it's about 5.6x cheaper per token
  • you process long inputs — it offers a 262,144 token context window
  • you want the most recent training data — it shipped Sep 2025

At a glance

The differences that matter most.

Core performance indexes
24.3
#157
21.8
#173
24.4
#149
22.2
#162
17.0
#116
19.5
#98
Cost, coverage & limits
Benchmark wins
0 of 1
1 of 1
Input price
$3.00 / M
$0.60 / M
Output price
$15.00 / M
$2.50 / M
Context window
200,000
262,144

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Sonnet 4
Kimi K2 0905
16.1#203
24.6#111
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

8 reported for Claude Sonnet 4 · 6 for Kimi K2 0905

1 shared

Claude Sonnet 4 outperforms in 0 benchmarks, while Kimi K2 0905 is better at 1 benchmark (GPQA).

Kimi K2 0905 significantly outperforms across most benchmarks.

Fri Sep 04 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Kimi K2 0905 costs less

For input processing, Claude Sonnet 4 ($3.00/1M tokens) is 5.0x more expensive than Kimi K2 0905 ($0.60/1M tokens).

For output processing, Claude Sonnet 4 ($15.00/1M tokens) is 6.0x more expensive than Kimi K2 0905 ($2.50/1M tokens).

In conclusion, Claude Sonnet 4 is more expensive than Kimi K2 0905.*

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

Lowest available price from all providers
Fri Sep 04 2026 • llm-stats.com
Anthropic
Claude Sonnet 4
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's 200,000 tokens. Kimi K2 0905 can generate longer responses up to 262,144 tokens, while Claude Sonnet 4 is limited to 64,000 tokens.

Anthropic
Claude Sonnet 4
Input200,000 tokens
Output64,000 tokens
Moonshot AI
Kimi K2 0905
Input262,144 tokens
Output262,144 tokens
Fri Sep 04 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Sonnet 4 supports multimodal inputs, whereas Kimi K2 0905 does not.

Claude Sonnet 4 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Sonnet 4

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

Proprietary

Closed source

Kimi K2 0905

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Sonnet 4 was released on 2025-05-22, while Kimi K2 0905 was released on 2025-09-05.

Kimi K2 0905 is 4 months newer than Claude Sonnet 4.

Claude Sonnet 4

May 22, 2025

1.3 years ago

Kimi K2 0905

Sep 5, 2025

12 months ago

3mo newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude Sonnet 4 is available from Anthropic, Bedrock, Google. Kimi K2 0905 is available from Novita.

Claude Sonnet 4

anthropic logo
Anthropic
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
bedrock logo
AWS Bedrock
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
google logo
Google
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

Judge for yourself.

Run your own prompts against Claude Sonnet 4 and Kimi K2 0905 side-by-side, then vote on the output you prefer.

Claude Sonnet 4
✓ Preferred
Kimi K2 0905
Open in Playground

FAQ

Common questions about Claude Sonnet 4 vs Kimi K2 0905.

Which is better, Claude Sonnet 4 or Kimi K2 0905?

Claude Sonnet 4 and Kimi K2 0905 are closely matched on the LLM Stats Score at 24.3 and 21.8. Claude Sonnet 4 is made by Anthropic and Kimi K2 0905 is made by Moonshot AI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Sonnet 4 compare to Kimi K2 0905 in benchmarks?

Claude Sonnet 4 scores MMMLU: 86.5%, TAU-bench Retail: 80.5%, GPQA: 75.4%, MMMU: 74.4%, SWE-Bench Verified: 72.7%. Kimi K2 0905 scores HumanEval: 94.5%, MMLU: 90.2%, MATH: 89.1%, MMLU-Pro: 82.5%, GPQA: 75.8%.

Is Claude Sonnet 4 cheaper than Kimi K2 0905?

Kimi K2 0905 is 5.0x cheaper for input tokens. Claude Sonnet 4 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.

What are the context window sizes for Claude Sonnet 4 and Kimi K2 0905?

Claude Sonnet 4 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.

What are the main differences between Claude Sonnet 4 and Kimi K2 0905?

Key differences include LLM Stats Score (24.3 vs 21.8), 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.

Who makes Claude Sonnet 4 and Kimi K2 0905?

Claude Sonnet 4 is developed by Anthropic and Kimi K2 0905 is developed by Moonshot AI.