Model Comparison

Kimi K3 vs GPT-5.6 LunaWhich is better in 2026?

Kimi K3 significantly outperforms across most benchmarks. GPT-5.6 Luna is 2.7x cheaper per token.

Verdict: Kimi K3 vs GPT-5.6 Luna — which is better?

Kimi K3 (by Moonshot AI) and GPT-5.6 Luna (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 K3 outperforms in 9 benchmarks (AutomationBench, BrowseComp, DeepSWE, GDPval-AA, GPQA, MMMU-Pro, MMMU-Pro (with tools), Terminal-Bench 2.1, Toolathlon), while GPT-5.6 Luna is better at 0 benchmarks. Kimi K3 significantly outperforms across most benchmarks.

On price, GPT-5.6 Luna is roughly 2.7x 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 Kimi K3 if…

  • you want the strongest raw capability — it leads on 9 of 9 shared benchmarks
  • you want the most recent training data — it shipped Jul 2026

Choose GPT-5.6 Luna if…

  • cost matters — it's about 2.7x cheaper per token
  • you process long inputs — it offers a 1,050,000 token context window

Performance Benchmarks

Comparative analysis across standard metrics

9 benchmarks

Kimi K3 outperforms in 9 benchmarks (AutomationBench, BrowseComp, DeepSWE, GDPval-AA, GPQA, MMMU-Pro, MMMU-Pro (with tools), Terminal-Bench 2.1, Toolathlon), while GPT-5.6 Luna is better at 0 benchmarks.

Kimi K3 significantly outperforms across most benchmarks.

Fri Jul 17 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GPT-5.6 Luna costs less

For input processing, Kimi K3 ($3.00/1M tokens) is 3.0x more expensive than GPT-5.6 Luna ($1.00/1M tokens).

For output processing, Kimi K3 ($15.00/1M tokens) is 2.5x more expensive than GPT-5.6 Luna ($6.00/1M tokens).

In conclusion, Kimi K3 is more expensive than GPT-5.6 Luna.*

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

Lowest available price from all providers
Fri Jul 17 2026 • llm-stats.com
Moonshot AI
Kimi K3
Input tokens$3.00
Output tokens$15.00
Best providerUnknown Organization
OpenAI
GPT-5.6 Luna
Input tokens$1.00
Output tokens$6.00
Best providerOpenAI
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 K3's 1,048,576 tokens. Kimi K3 can generate longer responses up to 1,048,576 tokens, while GPT-5.6 Luna is limited to 128,000 tokens.

Moonshot AI
Kimi K3
Input1,048,576 tokens
Output1,048,576 tokens
OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
Fri Jul 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Kimi K3 and GPT-5.6 Luna support multimodal inputs.

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

Kimi K3

Text
Images
Audio
Video

GPT-5.6 Luna

Text
Images
Audio
Video

Release Timeline

When each model was launched

Kimi K3 was released on 2026-07-16, while GPT-5.6 Luna was released on 2026-07-09.

Kimi K3 is 0 month newer than GPT-5.6 Luna.

Kimi K3

Jul 16, 2026

1 days ago

1w newer
GPT-5.6 Luna

Jul 9, 2026

1 weeks ago

Knowledge Cutoff

When training data ends

GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while Kimi K3'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 K3's cutoff date.

Kimi K3

—

GPT-5.6 Luna

Feb 2026

Provider Availability

Kimi K3 is available from Moonshot AI. GPT-5.6 Luna is available from OpenAI.

Kimi K3

moonshot logo
Unknown Organization
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M

GPT-5.6 Luna

openai logo
OpenAI
Input Price:Input: $1.00/1MOutput Price:Output: $6.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Moonshot AI
Has open weights
Higher AutomationBench score (30.8% vs 14.9%)
Higher BrowseComp score (91.2% vs 83.3%)
Higher DeepSWE score (67.5% vs 67.2%)
Higher GDPval-AA score (55.6% vs 53.1%)
Higher GPQA score (93.5% vs 92.3%)
Higher MMMU-Pro score (81.6% vs 78.4%)
Higher MMMU-Pro (with tools) score (83.4% vs 79.5%)
Higher Terminal-Bench 2.1 score (88.3% vs 84.7%)
Higher Toolathlon score (73.2% vs 53.4%)
OpenAI
Larger context window (1,050,000 tokens)
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Kimi K3 and GPT-5.6 Luna side-by-side, then vote on the output you prefer.

Kimi K3
✓ Preferred
GPT-5.6 Luna
Open in Playground
AI Model Comparison Table
Feature
Moonshot AI
Kimi K3
OpenAI
GPT-5.6 Luna

FAQ

Common questions about Kimi K3 vs GPT-5.6 Luna.

Which is better, Kimi K3 or GPT-5.6 Luna?

Kimi K3 significantly outperforms across most benchmarks. Kimi K3 is made by Moonshot AI and GPT-5.6 Luna is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Kimi K3 compare to GPT-5.6 Luna in benchmarks?

Kimi K3 scores MathVision: 97.8%, DeepSearchQA: 95.0%, GPQA: 93.5%, CharXiv-R: 91.3%, BrowseComp: 91.2%. 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%.

Is Kimi K3 cheaper than GPT-5.6 Luna?

GPT-5.6 Luna is 3.0x cheaper for input tokens. Kimi K3 costs $3.00/M input and $15.00/M output via moonshot. GPT-5.6 Luna costs $1.00/M input and $6.00/M output via openai.

What are the context window sizes for Kimi K3 and GPT-5.6 Luna?

Kimi K3 supports 1.0M tokens and GPT-5.6 Luna supports 1.1M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Kimi K3 and GPT-5.6 Luna?

Key differences include context window (1.0M vs 1.1M), input pricing ($3.00 vs $1.00/M), licensing (Unknown vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes Kimi K3 and GPT-5.6 Luna?

Kimi K3 is developed by Moonshot AI and GPT-5.6 Luna is developed by OpenAI.

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