Model Comparison
Kimi K2-Thinking-0905 vs o1-previewWhich is better in 2026?
Kimi K2-Thinking-0905 significantly outperforms across most benchmarks. Kimi K2-Thinking-0905 is 30.8x cheaper per token.
Verdict: Kimi K2-Thinking-0905 vs o1-preview — which is better?
Kimi K2-Thinking-0905 (by Moonshot AI) and o1-preview (by OpenAI) 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.
Kimi K2-Thinking-0905 outperforms in 2 benchmarks (GPQA, SWE-Bench Verified), while o1-preview is better at 0 benchmarks. Kimi K2-Thinking-0905 significantly outperforms across most benchmarks.
On price, Kimi K2-Thinking-0905 is roughly 30.8x 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 Kimi K2-Thinking-0905 if…
- you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
- cost matters — it's about 30.8x 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
- you need open weights you can self-host or fine-tune
Choose o1-preview if…
- you want predictable pricing at $15.00/M input and $60.00/M output
Performance Benchmarks
Comparative analysis across standard metrics
Kimi K2-Thinking-0905 outperforms in 2 benchmarks (GPQA, SWE-Bench Verified), while o1-preview is better at 0 benchmarks.
Kimi K2-Thinking-0905 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Kimi K2-Thinking-0905 ($0.47/1M tokens) is 31.9x cheaper than o1-preview ($15.00/1M tokens).
For output processing, Kimi K2-Thinking-0905 ($2.00/1M tokens) is 30.0x cheaper than o1-preview ($60.00/1M tokens).
In conclusion, o1-preview 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 o1-preview's 128,000 tokens. Kimi K2-Thinking-0905 can generate longer responses up to 262,144 tokens, while o1-preview is limited to 32,768 tokens.
License
Usage and distribution terms
Kimi K2-Thinking-0905 is licensed under MIT, while o1-preview uses a proprietary license.
License differences may affect how you can use these models in commercial or open-source projects.
MIT
Open weights
Proprietary
Closed source
Release Timeline
When each model was launched
Kimi K2-Thinking-0905 was released on 2025-09-05, while o1-preview was released on 2024-09-12.
Kimi K2-Thinking-0905 is 12 months newer than o1-preview.
Sep 5, 2025
9 months ago
11mo newerSep 12, 2024
1.7 years ago
Knowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Kimi K2-Thinking-0905 is available from DeepInfra, Novita, Fireworks. o1-preview is available from OpenAI, Azure.
Kimi K2-Thinking-0905
o1-preview
Outputs Comparison
Key Takeaways
Kimi K2-Thinking-0905
View detailsMoonshot AI
o1-preview
View detailsOpenAI
No standout differentiators in the data we have for this pair.
Detailed Comparison
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FAQ
Common questions about Kimi K2-Thinking-0905 vs o1-preview.