Model Comparison

Gemma 4 12B vs GPT-5.6 LunaWhich is better in 2026?

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

Verdict: Gemma 4 12B vs GPT-5.6 Luna — which is better?

Gemma 4 12B (by Google) 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.

Gemma 4 12B outperforms in 1 benchmarks (MRCR v2 (8-needle)), while GPT-5.6 Luna is better at 2 benchmarks (GPQA, MMMU-Pro). GPT-5.6 Luna shows notably better performance in the majority of benchmarks.

Choose Gemma 4 12B if…

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

Choose GPT-5.6 Luna if…

  • you want the strongest raw capability — it leads on 2 of 3 shared benchmarks
  • you want the most recent training data — it shipped Jul 2026

Performance Benchmarks

Comparative analysis across standard metrics

3 benchmarks

Gemma 4 12B outperforms in 1 benchmarks (MRCR v2 (8-needle)), while GPT-5.6 Luna is better at 2 benchmarks (GPQA, MMMU-Pro).

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

Fri Jul 17 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

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

Google
Gemma 4 12B
Input- tokens
Output- 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 Gemma 4 12B and GPT-5.6 Luna support multimodal inputs.

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

Gemma 4 12B

Text
Images
Audio
Video

GPT-5.6 Luna

Text
Images
Audio
Video

License

Usage and distribution terms

Gemma 4 12B is licensed under Apache 2.0, while GPT-5.6 Luna uses a proprietary license.

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

Gemma 4 12B

Apache 2.0

Open weights

GPT-5.6 Luna

Proprietary

Closed source

Release Timeline

When each model was launched

Gemma 4 12B was released on 2026-05-23, while GPT-5.6 Luna was released on 2026-07-09.

GPT-5.6 Luna is 2 months newer than Gemma 4 12B.

Gemma 4 12B

May 23, 2026

1 months ago

GPT-5.6 Luna

Jul 9, 2026

1 weeks ago

1mo newer

Knowledge Cutoff

When training data ends

Gemma 4 12B has a knowledge cutoff of 2025-01-01, while GPT-5.6 Luna has a cutoff of 2026-02-16.

GPT-5.6 Luna has more recent training data (up to 2026-02-16), making it potentially better informed about events through that date compared to Gemma 4 12B (2025-01-01).

Gemma 4 12B

Jan 2025

GPT-5.6 Luna

Feb 2026

1.1 yr newer

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Google
Has open weights
Higher MRCR v2 (8-needle) score (43.4% vs 41.3%)
OpenAI
Larger context window (1,050,000 tokens)
Higher GPQA score (92.3% vs 78.8%)
Higher MMMU-Pro score (78.4% vs 69.1%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Gemma 4 12B and GPT-5.6 Luna side-by-side, then vote on the output you prefer.

Gemma 4 12B
✓ Preferred
GPT-5.6 Luna
Open in Playground
AI Model Comparison Table
Feature
Google
Gemma 4 12B
OpenAI
GPT-5.6 Luna

FAQ

Common questions about Gemma 4 12B vs GPT-5.6 Luna.

Which is better, Gemma 4 12B or GPT-5.6 Luna?

GPT-5.6 Luna shows notably better performance in the majority of benchmarks. Gemma 4 12B is made by Google 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 Gemma 4 12B compare to GPT-5.6 Luna in benchmarks?

Gemma 4 12B scores FLEURS: 93.1%, MMMLU: 83.4%, MathVision: 79.7%, GPQA: 78.8%, AIME 2026: 77.5%. 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%.

What are the context window sizes for Gemma 4 12B and GPT-5.6 Luna?

Gemma 4 12B supports an unknown number of 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 Gemma 4 12B and GPT-5.6 Luna?

Key differences include licensing (Apache 2.0 vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemma 4 12B and GPT-5.6 Luna?

Gemma 4 12B is developed by Google and GPT-5.6 Luna is developed by OpenAI.

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