Model Comparison

Muse Spark vs GPT-5.6 LunaWhich is better in 2026?

GPT-5.6 Luna has a slight edge in benchmark performance.

Verdict: Muse Spark vs GPT-5.6 Luna — which is better?

Muse Spark (by Meta) 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.

Muse Spark outperforms in 2 benchmarks (HealthBench Hard, MMMU-Pro), while GPT-5.6 Luna is better at 3 benchmarks (GDPval-AA, GPQA, SWE-Bench Pro). GPT-5.6 Luna has a slight edge in benchmark performance.

Choose Muse Spark if…

  • you are already invested in the Meta ecosystem

Choose GPT-5.6 Luna if…

  • you want the strongest raw capability — it leads on 3 of 5 shared benchmarks
  • you want the most recent training data — it shipped Jul 2026

Performance Benchmarks

Comparative analysis across standard metrics

5 benchmarks

Muse Spark outperforms in 2 benchmarks (HealthBench Hard, MMMU-Pro), while GPT-5.6 Luna is better at 3 benchmarks (GDPval-AA, GPQA, SWE-Bench Pro).

GPT-5.6 Luna has a slight edge in benchmark performance.

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).

Meta
Muse Spark
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 Muse Spark and GPT-5.6 Luna support multimodal inputs.

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

Muse Spark

Text
Images
Audio
Video

GPT-5.6 Luna

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Muse Spark

Proprietary

Closed source

GPT-5.6 Luna

Proprietary

Closed source

Release Timeline

When each model was launched

Muse Spark was released on 2026-04-08, while GPT-5.6 Luna was released on 2026-07-09.

GPT-5.6 Luna is 3 months newer than Muse Spark.

Muse Spark

Apr 8, 2026

3 months ago

GPT-5.6 Luna

Jul 9, 2026

1 weeks ago

3mo newer

Knowledge Cutoff

When training data ends

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

Muse Spark

—

GPT-5.6 Luna

Feb 2026

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Meta
Higher HealthBench Hard score (42.8% vs 32.0%)
Higher MMMU-Pro score (80.4% vs 78.4%)
OpenAI
Larger context window (1,050,000 tokens)
Higher GDPval-AA score (53.1% vs 38.8%)
Higher GPQA score (92.3% vs 89.5%)
Higher SWE-Bench Pro score (62.7% vs 52.4%)

Detailed Comparison

Interactive Arena

Judge for yourself.

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

Muse Spark
✓ Preferred
GPT-5.6 Luna
Open in Playground
AI Model Comparison Table
Feature
Meta
Muse Spark
OpenAI
GPT-5.6 Luna

FAQ

Common questions about Muse Spark vs GPT-5.6 Luna.

Which is better, Muse Spark or GPT-5.6 Luna?

GPT-5.6 Luna has a slight edge in benchmark performance. Muse Spark is made by Meta 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 Muse Spark compare to GPT-5.6 Luna in benchmarks?

Muse Spark scores Tau2 Telecom: 91.5%, GPQA: 89.5%, CharXiv-R: 86.4%, ScreenSpot Pro: 84.1%, IPhO 2025: 82.6%. 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 Muse Spark and GPT-5.6 Luna?

Muse Spark 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.

Who makes Muse Spark and GPT-5.6 Luna?

Muse Spark is developed by Meta and GPT-5.6 Luna is developed by OpenAI.

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