Claude Sonnet 4 vs Kimi K2 Instruct
Claude Sonnet 4 and Kimi K2 Instruct are closely matched at 24.2 and 21.9 on the LLM Stats Score. Kimi K2 Instruct is 12.0x cheaper per token.
Anthropic · Moonshot AI · Updated for 2026
Which is better?
Claude Sonnet 4 and Kimi K2 Instruct are closely matched on the overall LLM Stats Score at 24.2 and 21.9.
In the 3 individual benchmarks reported for both models, Claude Sonnet 4 wins 3; this is a narrower head-to-head signal than the composite indexes.
On price, Kimi K2 Instruct is roughly 12.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Claude Sonnet 4
- you value its reported benchmark strengths — it wins 3 of 3 exact shared results
Choose Kimi K2 Instruct
- cost matters — it's about 12.0x cheaper per token
- you want the most recent training data — it shipped Jul 2025
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
8 reported for Claude Sonnet 4 · 38 for Kimi K2 Instruct
Claude Sonnet 4 outperforms in 3 benchmarks (AIME 2025, GPQA, Terminal-Bench), while Kimi K2 Instruct is better at 0 benchmarks.
Claude Sonnet 4 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Sonnet 4 ($3.00/1M tokens) is 6.0x more expensive than Kimi K2 Instruct ($0.50/1M tokens).
For output processing, Claude Sonnet 4 ($15.00/1M tokens) is 30.0x more expensive than Kimi K2 Instruct ($0.50/1M tokens).
In conclusion, Claude Sonnet 4 is more expensive than Kimi K2 Instruct.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Both models have the same input context window of 200,000 tokens. Kimi K2 Instruct can generate longer responses up to 200,000 tokens, while Claude Sonnet 4 is limited to 64,000 tokens.
Input capabilities
Documented input modalities across available providers
Claude Sonnet 4 supports multimodal inputs, whereas Kimi K2 Instruct 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
Kimi K2 Instruct
License
Usage and distribution terms
Claude Sonnet 4 is licensed under a proprietary license, while Kimi K2 Instruct uses MIT.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
MIT
Open weights
Release Timeline
When each model was launched
Claude Sonnet 4 was released on 2025-05-22, while Kimi K2 Instruct was released on 2025-07-11.
Kimi K2 Instruct is 2 months newer than Claude Sonnet 4.
May 22, 2025
1.3 years ago
Jul 11, 2025
1.2 years ago
1mo newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Claude Sonnet 4 is available from Anthropic, Bedrock, Google. Kimi K2 Instruct is available from Fireworks, Novita.
Claude Sonnet 4
Kimi K2 Instruct
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Sonnet 4 and Kimi K2 Instruct side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Sonnet 4 vs Kimi K2 Instruct.