Model Comparison
GPT-5.6 Terra vs Kimi K2.6Which is better in 2026?
GPT-5.6 Terra significantly outperforms across most benchmarks. Kimi K2.6 is 3.9x cheaper per token.
Verdict: GPT-5.6 Terra vs Kimi K2.6 — which is better?
GPT-5.6 Terra (by OpenAI) and Kimi K2.6 (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.
GPT-5.6 Terra outperforms in 6 benchmarks (BrowseComp, GDPval-AA, GPQA, MMMU-Pro, SWE-Bench Pro, Toolathlon), while Kimi K2.6 is better at 0 benchmarks. GPT-5.6 Terra significantly outperforms across most benchmarks.
On price, Kimi K2.6 is roughly 3.9x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.6 Terra also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose GPT-5.6 Terra if…
- you want the strongest raw capability — it leads on 6 of 6 shared benchmarks
- you process long inputs — it offers a 1,050,000 token context window
- you want the most recent training data — it shipped Jul 2026
Choose Kimi K2.6 if…
- cost matters — it's about 3.9x cheaper per token
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
GPT-5.6 Terra outperforms in 6 benchmarks (BrowseComp, GDPval-AA, GPQA, MMMU-Pro, SWE-Bench Pro, Toolathlon), while Kimi K2.6 is better at 0 benchmarks.
GPT-5.6 Terra significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.6 Terra ($2.50/1M tokens) is 3.3x more expensive than Kimi K2.6 ($0.75/1M tokens).
For output processing, GPT-5.6 Terra ($15.00/1M tokens) is 4.3x more expensive than Kimi K2.6 ($3.50/1M tokens).
In conclusion, GPT-5.6 Terra is more expensive than Kimi K2.6.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.6 Terra accepts 1,050,000 input tokens compared to Kimi K2.6's 262,144 tokens. Kimi K2.6 can generate longer responses up to 131,072 tokens, while GPT-5.6 Terra is limited to 128,000 tokens.
Input Capabilities
Supported data types and modalities
Both GPT-5.6 Terra and Kimi K2.6 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.6 Terra
Kimi K2.6
License
Usage and distribution terms
GPT-5.6 Terra is licensed under a proprietary license, while Kimi K2.6 uses Modified MIT License.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
Modified MIT License
Open weights
Release Timeline
When each model was launched
GPT-5.6 Terra was released on 2026-07-09, while Kimi K2.6 was released on 2026-04-20.
GPT-5.6 Terra is 3 months newer than Kimi K2.6.
Jul 9, 2026
1 weeks ago
2mo newerApr 20, 2026
3 months ago
Knowledge Cutoff
When training data ends
GPT-5.6 Terra has a documented knowledge cutoff of 2026-02-16, while Kimi K2.6's cutoff date is not specified.
We can confirm GPT-5.6 Terra's training data extends to 2026-02-16, but cannot make a direct comparison without Kimi K2.6's cutoff date.
Feb 2026
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Provider Availability
GPT-5.6 Terra is available from OpenAI. Kimi K2.6 is available from DeepInfra, Fireworks, Moonshot AI, Novita, Together.
GPT-5.6 Terra
Kimi K2.6
Outputs Comparison
Key Takeaways
Kimi K2.6
View detailsMoonshot AI
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GPT-5.6 Terra and Kimi K2.6 side-by-side, then vote on the output you prefer.
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FAQ
Common questions about GPT-5.6 Terra vs Kimi K2.6.