Model Comparison

GPT-5.6 Luna vs MedGemma 4B ITWhich is better in 2026?

Comparing GPT-5.6 Luna and MedGemma 4B IT across benchmarks, pricing, and capabilities.

Verdict: GPT-5.6 Luna vs MedGemma 4B IT — which is better?

GPT-5.6 Luna (by OpenAI) and MedGemma 4B IT (by Google) 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.

Choose GPT-5.6 Luna if…

  • you want the most recent training data — it shipped Jul 2026

Choose MedGemma 4B IT if…

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

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

GPT-5.6 Luna and MedGemma 4B ITdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

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).

OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
Google
MedGemma 4B IT
Input- tokens
Output- tokens
Sat Jul 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-5.6 Luna and MedGemma 4B IT 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

MedGemma 4B IT

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-5.6 Luna is licensed under a proprietary license, while MedGemma 4B IT uses Health AI Developer Foundations terms of use.

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

GPT-5.6 Luna

Proprietary

Closed source

MedGemma 4B IT

Health AI Developer Foundations terms of use

Open weights

Release Timeline

When each model was launched

GPT-5.6 Luna was released on 2026-07-09, while MedGemma 4B IT was released on 2025-05-20.

GPT-5.6 Luna is 14 months newer than MedGemma 4B IT.

GPT-5.6 Luna

Jul 9, 2026

2 weeks ago

1.1yr newer
MedGemma 4B IT

May 20, 2025

1.2 years ago

Knowledge Cutoff

When training data ends

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

GPT-5.6 Luna

Feb 2026

MedGemma 4B IT

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Outputs Comparison

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Key Takeaways

OpenAI
Larger context window (1,050,000 tokens)
Google
Has open weights

Detailed Comparison

Interactive Arena

Judge for yourself.

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

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

FAQ

Common questions about GPT-5.6 Luna vs MedGemma 4B IT.

Which is better, GPT-5.6 Luna or MedGemma 4B IT?

GPT-5.6 Luna (OpenAI) and MedGemma 4B IT (Google) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does GPT-5.6 Luna compare to MedGemma 4B IT 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%. MedGemma 4B IT scores MIMIC CXR: 88.9%, DermMCQA: 71.8%, PathMCQA: 69.8%, SlakeVQA: 62.3%, VQA-Rad: 49.9%.

What are the context window sizes for GPT-5.6 Luna and MedGemma 4B IT?

GPT-5.6 Luna supports 1.1M tokens and MedGemma 4B IT 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 Luna and MedGemma 4B IT?

Key differences include licensing (Proprietary vs Health AI Developer Foundations terms of use). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.6 Luna and MedGemma 4B IT?

GPT-5.6 Luna is developed by OpenAI and MedGemma 4B IT is developed by Google.

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