Model Comparison
Claude Opus 4.5 vs Kimi K2-Thinking-0905Which is better in 2026?
Claude Opus 4.5 significantly outperforms across most benchmarks. Kimi K2-Thinking-0905 is 11.7x cheaper per token.
Verdict: Claude Opus 4.5 vs Kimi K2-Thinking-0905 — which is better?
Claude Opus 4.5 (by Anthropic) and Kimi K2-Thinking-0905 (by Moonshot AI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
Claude Opus 4.5 outperforms in 2 benchmarks (GPQA, SWE-Bench Verified), while Kimi K2-Thinking-0905 is better at 0 benchmarks. Claude Opus 4.5 significantly outperforms across most benchmarks.
On price, Kimi K2-Thinking-0905 is roughly 11.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Kimi K2-Thinking-0905 also accepts a larger context window (262,144 input tokens), making it the stronger choice for long documents and large codebases.
Choose Claude Opus 4.5 if…
- you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
- you want the most recent training data — it shipped Nov 2025
Choose Kimi K2-Thinking-0905 if…
- cost matters — it's about 11.7x cheaper per token
- you process long inputs — it offers a 262,144 token context window
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
Claude Opus 4.5 outperforms in 2 benchmarks (GPQA, SWE-Bench Verified), while Kimi K2-Thinking-0905 is better at 0 benchmarks.
Claude Opus 4.5 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Opus 4.5 ($5.00/1M tokens) is 10.6x more expensive than Kimi K2-Thinking-0905 ($0.47/1M tokens).
For output processing, Claude Opus 4.5 ($25.00/1M tokens) is 12.5x more expensive than Kimi K2-Thinking-0905 ($2.00/1M tokens).
In conclusion, Claude Opus 4.5 is more expensive than Kimi K2-Thinking-0905.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Kimi K2-Thinking-0905 accepts 262,144 input tokens compared to Claude Opus 4.5's 200,000 tokens. Kimi K2-Thinking-0905 can generate longer responses up to 262,144 tokens, while Claude Opus 4.5 is limited to 64,000 tokens.
Input Capabilities
Supported data types and modalities
Claude Opus 4.5 supports multimodal inputs, whereas Kimi K2-Thinking-0905 does not.
Claude Opus 4.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.
Claude Opus 4.5
Kimi K2-Thinking-0905
License
Usage and distribution terms
Claude Opus 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.
Proprietary
Closed source
MIT
Open weights
Release Timeline
When each model was launched
Claude Opus 4.5 was released on 2025-11-24, while Kimi K2-Thinking-0905 was released on 2025-09-05.
Claude Opus 4.5 is 3 months newer than Kimi K2-Thinking-0905.
Nov 24, 2025
6 months ago
2mo newerSep 5, 2025
9 months ago
Knowledge Cutoff
When training data ends
Claude Opus 4.5 has a documented knowledge cutoff of 2025-03-31, while Kimi K2-Thinking-0905's cutoff date is not specified.
We can confirm Claude Opus 4.5's training data extends to 2025-03-31, but cannot make a direct comparison without Kimi K2-Thinking-0905's cutoff date.
Mar 2025
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Provider Availability
Claude Opus 4.5 is available from Anthropic. Kimi K2-Thinking-0905 is available from DeepInfra, Novita, Fireworks.
Claude Opus 4.5
Kimi K2-Thinking-0905
Outputs Comparison
Key Takeaways
Claude Opus 4.5
View detailsAnthropic
Kimi K2-Thinking-0905
View detailsMoonshot AI
Detailed Comparison
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FAQ
Common questions about Claude Opus 4.5 vs Kimi K2-Thinking-0905.