Model Comparison

GLM-4.5-Air vs GPT-5.6 LunaWhich is better in 2026?

GPT-5.6 Luna significantly outperforms across most benchmarks.

Verdict: GLM-4.5-Air vs GPT-5.6 Luna — which is better?

GLM-4.5-Air (by Zhipu 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.

GLM-4.5-Air outperforms in 0 benchmarks, while GPT-5.6 Luna is better at 2 benchmarks (BrowseComp, GPQA). GPT-5.6 Luna significantly outperforms across most benchmarks.

Choose GLM-4.5-Air 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 2 shared benchmarks
  • you want the most recent training data — it shipped Jul 2026

Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

GLM-4.5-Air outperforms in 0 benchmarks, while GPT-5.6 Luna is better at 2 benchmarks (BrowseComp, GPQA).

GPT-5.6 Luna significantly outperforms across most benchmarks.

Sun Jul 26 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).

Zhipu AI
GLM-4.5-Air
Input- tokens
Output- tokens
OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
Sun Jul 26 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5.6 Luna supports multimodal inputs, whereas GLM-4.5-Air does not.

GPT-5.6 Luna can handle both text and other forms of data like images, making it suitable for multimodal applications.

GLM-4.5-Air

Text
Images
Audio
Video

GPT-5.6 Luna

Text
Images
Audio
Video

License

Usage and distribution terms

GLM-4.5-Air is licensed under MIT, 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.

GLM-4.5-Air

MIT

Open weights

GPT-5.6 Luna

Proprietary

Closed source

Release Timeline

When each model was launched

GLM-4.5-Air was released on 2025-07-28, while GPT-5.6 Luna was released on 2026-07-09.

GPT-5.6 Luna is 12 months newer than GLM-4.5-Air.

GLM-4.5-Air

Jul 28, 2025

12 months ago

GPT-5.6 Luna

Jul 9, 2026

2 weeks ago

11mo newer

Knowledge Cutoff

When training data ends

GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while GLM-4.5-Air'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 GLM-4.5-Air's cutoff date.

GLM-4.5-Air

—

GPT-5.6 Luna

Feb 2026

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Zhipu AI
Has open weights
OpenAI
Larger context window (1,050,000 tokens)
Supports multimodal inputs
Higher BrowseComp score (83.3% vs 21.3%)
Higher GPQA score (92.3% vs 75.0%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against GLM-4.5-Air and GPT-5.6 Luna side-by-side, then vote on the output you prefer.

GLM-4.5-Air
✓ Preferred
GPT-5.6 Luna
Open in Playground
AI Model Comparison Table
Feature
Zhipu AI
GLM-4.5-Air
OpenAI
GPT-5.6 Luna

FAQ

Common questions about GLM-4.5-Air vs GPT-5.6 Luna.

Which is better, GLM-4.5-Air or GPT-5.6 Luna?

GPT-5.6 Luna significantly outperforms across most benchmarks. GLM-4.5-Air is made by Zhipu 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 GLM-4.5-Air compare to GPT-5.6 Luna in benchmarks?

GLM-4.5-Air scores MATH-500: 98.1%, AIME 2024: 89.4%, MMLU-Pro: 81.4%, TAU-bench Retail: 77.9%, BFCL-v3: 76.4%. 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 GLM-4.5-Air and GPT-5.6 Luna?

GLM-4.5-Air 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 GLM-4.5-Air and GPT-5.6 Luna?

Key differences include multimodal support (no vs yes), licensing (MIT vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes GLM-4.5-Air and GPT-5.6 Luna?

GLM-4.5-Air is developed by Zhipu AI and GPT-5.6 Luna is developed by OpenAI.

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