Model Comparison

GPT-5.6 Sol vs Kimi K2-Instruct-0905Which is better in 2026?

GPT-5.6 Sol significantly outperforms across most benchmarks.

Verdict: GPT-5.6 Sol vs Kimi K2-Instruct-0905 — which is better?

GPT-5.6 Sol (by OpenAI) and Kimi K2-Instruct-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.

GPT-5.6 Sol outperforms in 1 benchmarks (GPQA), while Kimi K2-Instruct-0905 is better at 0 benchmarks. GPT-5.6 Sol significantly outperforms across most benchmarks.

Choose GPT-5.6 Sol if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • you want the most recent training data — it shipped Jul 2026

Choose Kimi K2-Instruct-0905 if…

  • you need open weights you can self-host or fine-tune

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

GPT-5.6 Sol outperforms in 1 benchmarks (GPQA), while Kimi K2-Instruct-0905 is better at 0 benchmarks.

GPT-5.6 Sol significantly outperforms across most benchmarks.

Tue Jul 21 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only GPT-5.6 Sol specifies input context (1,050,000 tokens). Only GPT-5.6 Sol specifies output context (128,000 tokens).

OpenAI
GPT-5.6 Sol
Input1,050,000 tokens
Output128,000 tokens
Moonshot AI
Kimi K2-Instruct-0905
Input- tokens
Output- tokens
Tue Jul 21 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5.6 Sol supports multimodal inputs, whereas Kimi K2-Instruct-0905 does not.

GPT-5.6 Sol can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-5.6 Sol

Text
Images
Audio
Video

Kimi K2-Instruct-0905

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-5.6 Sol is licensed under a proprietary license, while Kimi K2-Instruct-0905 uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

GPT-5.6 Sol

Proprietary

Closed source

Kimi K2-Instruct-0905

MIT

Open weights

Release Timeline

When each model was launched

GPT-5.6 Sol was released on 2026-07-09, while Kimi K2-Instruct-0905 was released on 2025-09-05.

GPT-5.6 Sol is 10 months newer than Kimi K2-Instruct-0905.

GPT-5.6 Sol

Jul 9, 2026

1 weeks ago

10mo newer
Kimi K2-Instruct-0905

Sep 5, 2025

10 months ago

Knowledge Cutoff

When training data ends

GPT-5.6 Sol has a documented knowledge cutoff of 2026-02-16, while Kimi K2-Instruct-0905's cutoff date is not specified.

We can confirm GPT-5.6 Sol's training data extends to 2026-02-16, but cannot make a direct comparison without Kimi K2-Instruct-0905's cutoff date.

GPT-5.6 Sol

Feb 2026

Kimi K2-Instruct-0905

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Outputs Comparison

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Key Takeaways

OpenAI
Larger context window (1,050,000 tokens)
Supports multimodal inputs
Higher GPQA score (94.6% vs 75.1%)
Moonshot AI
Has open weights

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against GPT-5.6 Sol and Kimi K2-Instruct-0905 side-by-side, then vote on the output you prefer.

GPT-5.6 Sol
✓ Preferred
Kimi K2-Instruct-0905
Open in Playground
AI Model Comparison Table
Feature
OpenAI
GPT-5.6 Sol
Moonshot AI
Kimi K2-Instruct-0905

FAQ

Common questions about GPT-5.6 Sol vs Kimi K2-Instruct-0905.

Which is better, GPT-5.6 Sol or Kimi K2-Instruct-0905?

GPT-5.6 Sol significantly outperforms across most benchmarks. GPT-5.6 Sol is made by OpenAI and Kimi K2-Instruct-0905 is made by Moonshot AI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does GPT-5.6 Sol compare to Kimi K2-Instruct-0905 in benchmarks?

GPT-5.6 Sol scores Connectors: 100.0%, Capture-the-Flag Challenges (Internal): 96.7%, HealthBench Consensus: 95.5%, GPQA: 94.6%, MRCR v2 (8-needle): 91.5%. Kimi K2-Instruct-0905 scores MATH-500: 97.4%, MMLU-Redux: 92.7%, IFEval: 89.8%, AutoLogi: 89.5%, MMLU: 89.5%.

What are the context window sizes for GPT-5.6 Sol and Kimi K2-Instruct-0905?

GPT-5.6 Sol supports 1.1M tokens and Kimi K2-Instruct-0905 supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-5.6 Sol and Kimi K2-Instruct-0905?

Key differences include multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.6 Sol and Kimi K2-Instruct-0905?

GPT-5.6 Sol is developed by OpenAI and Kimi K2-Instruct-0905 is developed by Moonshot AI.

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