Model Comparison

GPT-5.6 Luna vs Mistral Small 4Which is better in 2026?

GPT-5.6 Luna significantly outperforms across most benchmarks. Mistral Small 4 is 8.6x cheaper per token.

Verdict: GPT-5.6 Luna vs Mistral Small 4 — which is better?

GPT-5.6 Luna (by OpenAI) and Mistral Small 4 (by Mistral 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 2 benchmarks (GPQA, MMMU-Pro), while Mistral Small 4 is better at 0 benchmarks. GPT-5.6 Luna significantly outperforms across most benchmarks.

On price, Mistral Small 4 is roughly 8.6x 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 2 of 2 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 Mistral Small 4 if…

  • cost matters — it's about 8.6x cheaper per token
  • you need open weights you can self-host or fine-tune

Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

GPT-5.6 Luna outperforms in 2 benchmarks (GPQA, MMMU-Pro), while Mistral Small 4 is better at 0 benchmarks.

GPT-5.6 Luna significantly outperforms across most benchmarks.

Mon Jul 27 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Mistral Small 4 costs less

For input processing, GPT-5.6 Luna ($1.00/1M tokens) is 6.7x more expensive than Mistral Small 4 ($0.15/1M tokens).

For output processing, GPT-5.6 Luna ($6.00/1M tokens) is 10.0x more expensive than Mistral Small 4 ($0.60/1M tokens).

In conclusion, GPT-5.6 Luna is more expensive than Mistral Small 4.*

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

Lowest available price from all providers
Mon Jul 27 2026 • llm-stats.com
OpenAI
GPT-5.6 Luna
Input tokens$1.00
Output tokens$6.00
Best providerOpenAI
Mistral AI
Mistral Small 4
Input tokens$0.15
Output tokens$0.60
Best providerMistral
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 Mistral Small 4's 256,000 tokens. Mistral Small 4 can generate longer responses up to 256,000 tokens, while GPT-5.6 Luna is limited to 128,000 tokens.

OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
Mistral AI
Mistral Small 4
Input256,000 tokens
Output256,000 tokens
Mon Jul 27 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-5.6 Luna and Mistral Small 4 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

Mistral Small 4

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-5.6 Luna is licensed under a proprietary license, while Mistral Small 4 uses Apache 2.0.

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

GPT-5.6 Luna

Proprietary

Closed source

Mistral Small 4

Apache 2.0

Open weights

Release Timeline

When each model was launched

GPT-5.6 Luna was released on 2026-07-09, while Mistral Small 4 was released on 2026-03-16.

GPT-5.6 Luna is 4 months newer than Mistral Small 4.

GPT-5.6 Luna

Jul 9, 2026

2 weeks ago

3mo newer
Mistral Small 4

Mar 16, 2026

4 months ago

Knowledge Cutoff

When training data ends

GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while Mistral Small 4'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 Mistral Small 4's cutoff date.

GPT-5.6 Luna

Feb 2026

Mistral Small 4

—

Provider Availability

GPT-5.6 Luna is available from OpenAI. Mistral Small 4 is available from Mistral AI.

GPT-5.6 Luna

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

Mistral Small 4

mistral logo
Mistral
Input Price:Input: $0.15/1MOutput Price:Output: $0.60/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

OpenAI
Larger context window (1,050,000 tokens)
Higher GPQA score (92.3% vs 71.2%)
Higher MMMU-Pro score (78.4% vs 60.0%)
Mistral AI
Less expensive input tokens
Less expensive output tokens
Has open weights

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against GPT-5.6 Luna and Mistral Small 4 side-by-side, then vote on the output you prefer.

GPT-5.6 Luna
✓ Preferred
Mistral Small 4
Open in Playground
AI Model Comparison Table
Feature
OpenAI
GPT-5.6 Luna
Mistral AI
Mistral Small 4

FAQ

Common questions about GPT-5.6 Luna vs Mistral Small 4.

Which is better, GPT-5.6 Luna or Mistral Small 4?

GPT-5.6 Luna significantly outperforms across most benchmarks. GPT-5.6 Luna is made by OpenAI and Mistral Small 4 is made by Mistral 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 Mistral Small 4 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%. Mistral Small 4 scores AIME 2025: 83.8%, MMLU-Pro: 78.0%, AA-LCR: 71.2%, GPQA: 71.2%, LiveCodeBench: 63.6%.

Is GPT-5.6 Luna cheaper than Mistral Small 4?

Mistral Small 4 is 6.7x cheaper for input tokens. GPT-5.6 Luna costs $1.00/M input and $6.00/M output via openai. Mistral Small 4 costs $0.15/M input and $0.60/M output via mistral.

What are the context window sizes for GPT-5.6 Luna and Mistral Small 4?

GPT-5.6 Luna supports 1.1M tokens and Mistral Small 4 supports 256K 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 Mistral Small 4?

Key differences include context window (1.1M vs 256K), input pricing ($1.00 vs $0.15/M), licensing (Proprietary vs Apache 2.0). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.6 Luna and Mistral Small 4?

GPT-5.6 Luna is developed by OpenAI and Mistral Small 4 is developed by Mistral AI.

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