Claude 3.5 Sonnet vs Kimi K2 0905
Kimi K2 0905 significantly outperforms across most benchmarks. Kimi K2 0905 is 5.6x cheaper per token.
Anthropic · Moonshot AI · Updated for 2026
Which is better?
Claude 3.5 Sonnet outperforms in 1 benchmarks (MMLU), while Kimi K2 0905 is better at 4 benchmarks (GPQA, HumanEval, MATH, MMLU-Pro). Kimi K2 0905 significantly outperforms across most benchmarks.
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 benchmark, pricing, and model metadata for 2026.
Choose Claude 3.5 Sonnet
- you want predictable pricing at $3.00/M input and $15.00/M output
Choose Kimi K2 0905
- you want the strongest raw capability — it leads on 4 of 5 shared benchmarks
- 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.
Performance Benchmarks
Comparative analysis across standard metrics
Claude 3.5 Sonnet outperforms in 1 benchmarks (MMLU), while Kimi K2 0905 is better at 4 benchmarks (GPQA, HumanEval, MATH, MMLU-Pro).
Kimi K2 0905 significantly outperforms across most benchmarks.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude 3.5 Sonnet ($3.00/1M tokens) is 5.0x more expensive than Kimi K2 0905 ($0.60/1M tokens).
For output processing, Claude 3.5 Sonnet ($15.00/1M tokens) is 6.0x more expensive than Kimi K2 0905 ($2.50/1M tokens).
In conclusion, Claude 3.5 Sonnet is more expensive than Kimi K2 0905.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Kimi K2 0905 accepts 262,144 input tokens compared to Claude 3.5 Sonnet's 200,000 tokens. Kimi K2 0905 can generate longer responses up to 262,144 tokens, while Claude 3.5 Sonnet is limited to 200,000 tokens.
Input Capabilities
Supported data types and modalities
Claude 3.5 Sonnet supports multimodal inputs, whereas Kimi K2 0905 does not.
Claude 3.5 Sonnet can handle both text and other forms of data like images, making it suitable for multimodal applications.
Claude 3.5 Sonnet
Kimi K2 0905
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Claude 3.5 Sonnet was released on 2024-06-21, while Kimi K2 0905 was released on 2025-09-05.
Kimi K2 0905 is 15 months newer than Claude 3.5 Sonnet.
Jun 21, 2024
2.2 years ago
Sep 5, 2025
11 months ago
1.2yr 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 3.5 Sonnet is available from Bedrock, Google. Kimi K2 0905 is available from Novita.
Claude 3.5 Sonnet
Kimi K2 0905
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude 3.5 Sonnet and Kimi K2 0905 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude 3.5 Sonnet vs Kimi K2 0905.