Model Comparison

GPT-5.6 Luna vs Kimi K2.6Which is better in 2026?

GPT-5.6 Luna shows notably better performance in the majority of benchmarks. Kimi K2.6 is 1.6x cheaper per token.

Verdict: GPT-5.6 Luna vs Kimi K2.6 — which is better?

GPT-5.6 Luna (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 Luna outperforms in 4 benchmarks (GDPval-AA, GPQA, SWE-Bench Pro, Toolathlon), while Kimi K2.6 is better at 2 benchmarks (BrowseComp, MMMU-Pro). GPT-5.6 Luna shows notably better performance in the majority of benchmarks.

On price, Kimi K2.6 is roughly 1.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5.6 Luna 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 Luna if…

  • you want the strongest raw capability — it leads on 4 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 1.6x cheaper per token
  • you need open weights you can self-host or fine-tune

Performance Benchmarks

Comparative analysis across standard metrics

6 benchmarks

GPT-5.6 Luna outperforms in 4 benchmarks (GDPval-AA, GPQA, SWE-Bench Pro, Toolathlon), while Kimi K2.6 is better at 2 benchmarks (BrowseComp, MMMU-Pro).

GPT-5.6 Luna shows notably better performance in the majority of benchmarks.

Tue Jul 21 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Kimi K2.6 costs less

For input processing, GPT-5.6 Luna ($1.00/1M tokens) is 1.3x more expensive than Kimi K2.6 ($0.75/1M tokens).

For output processing, GPT-5.6 Luna ($6.00/1M tokens) is 1.7x more expensive than Kimi K2.6 ($3.50/1M tokens).

In conclusion, GPT-5.6 Luna is more expensive than Kimi K2.6.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Tue Jul 21 2026 • llm-stats.com
OpenAI
GPT-5.6 Luna
Input tokens$1.00
Output tokens$6.00
Best providerOpenAI
Moonshot AI
Kimi K2.6
Input tokens$0.75
Output tokens$3.50
Best providerDeepinfra
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-5.6 Luna 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 Luna is limited to 128,000 tokens.

OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
Moonshot AI
Kimi K2.6
Input262,144 tokens
Output131,072 tokens
Tue Jul 21 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-5.6 Luna and Kimi K2.6 support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

GPT-5.6 Luna

Text
Images
Audio
Video

Kimi K2.6

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-5.6 Luna 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.

GPT-5.6 Luna

Proprietary

Closed source

Kimi K2.6

Modified MIT License

Open weights

Release Timeline

When each model was launched

GPT-5.6 Luna was released on 2026-07-09, while Kimi K2.6 was released on 2026-04-20.

GPT-5.6 Luna is 3 months newer than Kimi K2.6.

GPT-5.6 Luna

Jul 9, 2026

1 weeks ago

2mo newer
Kimi K2.6

Apr 20, 2026

3 months ago

Knowledge Cutoff

When training data ends

GPT-5.6 Luna 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 Luna's training data extends to 2026-02-16, but cannot make a direct comparison without Kimi K2.6's cutoff date.

GPT-5.6 Luna

Feb 2026

Kimi K2.6

—

Provider Availability

GPT-5.6 Luna is available from OpenAI. Kimi K2.6 is available from DeepInfra, Fireworks, Moonshot AI, Novita, Together.

GPT-5.6 Luna

openai logo
OpenAI
Input Price:Input: $1.00/1MOutput Price:Output: $6.00/1M

Kimi K2.6

deepinfra logo
Deepinfra
Input Price:Input: $0.75/1MOutput Price:Output: $3.50/1M
fireworks logo
Fireworks
Input Price:Input: $0.95/1MOutput Price:Output: $4.00/1M
moonshot logo
Unknown Organization
Input Price:Input: $0.95/1MOutput Price:Output: $4.00/1M
novita logo
Novita
Input Price:Input: $0.95/1MOutput Price:Output: $4.00/1M
together logo
Together
Input Price:Input: $1.20/1MOutput Price:Output: $4.50/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

OpenAI
Larger context window (1,050,000 tokens)
Higher GDPval-AA score (53.1% vs 40.1%)
Higher GPQA score (92.3% vs 90.5%)
Higher SWE-Bench Pro score (62.7% vs 58.6%)
Higher Toolathlon score (53.4% vs 50.0%)
Moonshot AI
Less expensive input tokens
Less expensive output tokens
Has open weights
Higher BrowseComp score (86.3% vs 83.3%)
Higher MMMU-Pro score (80.1% vs 78.4%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against GPT-5.6 Luna and Kimi K2.6 side-by-side, then vote on the output you prefer.

GPT-5.6 Luna
✓ Preferred
Kimi K2.6
Open in Playground
AI Model Comparison Table
Feature
OpenAI
GPT-5.6 Luna
Moonshot AI
Kimi K2.6

FAQ

Common questions about GPT-5.6 Luna vs Kimi K2.6.

Which is better, GPT-5.6 Luna or Kimi K2.6?

GPT-5.6 Luna shows notably better performance in the majority of benchmarks. GPT-5.6 Luna is made by OpenAI and Kimi K2.6 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 Luna compare to Kimi K2.6 in benchmarks?

GPT-5.6 Luna scores Connectors: 99.9%, HealthBench Consensus: 95.1%, GPQA: 92.3%, Search and Function-Calling: 89.7%, Capture-the-Flag Challenges (Internal): 85.2%. Kimi K2.6 scores V*: 96.9%, AIME 2026: 96.4%, MathVision: 93.2%, HMMT Feb 26: 92.7%, GPQA: 90.5%.

Is GPT-5.6 Luna cheaper than Kimi K2.6?

Kimi K2.6 is 1.3x cheaper for input tokens. GPT-5.6 Luna costs $1.00/M input and $6.00/M output via openai. Kimi K2.6 costs $0.75/M input and $3.50/M output via deepinfra.

What are the context window sizes for GPT-5.6 Luna and Kimi K2.6?

GPT-5.6 Luna supports 1.1M tokens and Kimi K2.6 supports 262K 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 Luna and Kimi K2.6?

Key differences include context window (1.1M vs 262K), input pricing ($1.00 vs $0.75/M), licensing (Proprietary vs Modified MIT License). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.6 Luna and Kimi K2.6?

GPT-5.6 Luna is developed by OpenAI and Kimi K2.6 is developed by Moonshot AI.

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