Model Comparison

GPT-5.6 Luna vs GLM-5.1Which is better in 2026?

GPT-5.6 Luna significantly outperforms across most benchmarks. GLM-5.1 is 1.0x cheaper per token.

Verdict: GPT-5.6 Luna vs GLM-5.1 — which is better?

GPT-5.6 Luna (by OpenAI) and GLM-5.1 (by Zhipu 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 5 benchmarks (BrowseComp, GDPval-AA, GPQA, SWE-Bench Pro, Toolathlon), while GLM-5.1 is better at 0 benchmarks. GPT-5.6 Luna significantly outperforms across most benchmarks.

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 5 of 5 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 GLM-5.1 if…

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

Performance Benchmarks

Comparative analysis across standard metrics

5 benchmarks

GPT-5.6 Luna outperforms in 5 benchmarks (BrowseComp, GDPval-AA, GPQA, SWE-Bench Pro, Toolathlon), while GLM-5.1 is better at 0 benchmarks.

GPT-5.6 Luna significantly outperforms across most benchmarks.

Fri Jul 17 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GLM-5.1 costs less

For input processing, GPT-5.6 Luna ($1.00/1M tokens) is 1.4x cheaper than GLM-5.1 ($1.40/1M tokens).

For output processing, GPT-5.6 Luna ($6.00/1M tokens) is 1.4x more expensive than GLM-5.1 ($4.40/1M tokens).

In conclusion, GPT-5.6 Luna is more expensive than GLM-5.1.*

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

Lowest available price from all providers
Fri Jul 17 2026 • llm-stats.com
OpenAI
GPT-5.6 Luna
Input tokens$1.00
Output tokens$6.00
Best providerOpenAI
Zhipu AI
GLM-5.1
Input tokens$1.40
Output tokens$4.40
Best providerFriendliAI
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 GLM-5.1's 200,000 tokens. Both models can generate responses up to 128,000 tokens.

OpenAI
GPT-5.6 Luna
Input1,050,000 tokens
Output128,000 tokens
Zhipu AI
GLM-5.1
Input200,000 tokens
Output128,000 tokens
Fri Jul 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5.6 Luna supports multimodal inputs, whereas GLM-5.1 does not.

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

GPT-5.6 Luna

Text
Images
Audio
Video

GLM-5.1

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-5.6 Luna is licensed under a proprietary license, while GLM-5.1 uses MIT.

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

GPT-5.6 Luna

Proprietary

Closed source

GLM-5.1

MIT

Open weights

Release Timeline

When each model was launched

GPT-5.6 Luna was released on 2026-07-09, while GLM-5.1 was released on 2026-04-07.

GPT-5.6 Luna is 3 months newer than GLM-5.1.

GPT-5.6 Luna

Jul 9, 2026

1 weeks ago

3mo newer
GLM-5.1

Apr 7, 2026

3 months ago

Knowledge Cutoff

When training data ends

GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while GLM-5.1'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-5.1's cutoff date.

GPT-5.6 Luna

Feb 2026

GLM-5.1

—

Provider Availability

GPT-5.6 Luna is available from OpenAI. GLM-5.1 is available from FriendliAI, ZAI.

GPT-5.6 Luna

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

GLM-5.1

friendli logo
FriendliAI
Input Price:Input: $1.40/1MOutput Price:Output: $4.40/1M
z logo
Unknown Organization
Input Price:Input: $1.40/1MOutput Price:Output: $4.40/1M
* 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)
Supports multimodal inputs
Less expensive input tokens
Higher BrowseComp score (83.3% vs 79.3%)
Higher GDPval-AA score (53.1% vs 42.7%)
Higher GPQA score (92.3% vs 86.2%)
Higher SWE-Bench Pro score (62.7% vs 58.4%)
Higher Toolathlon score (53.4% vs 40.7%)
Zhipu AI
Less expensive output tokens
Has open weights

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against GPT-5.6 Luna and GLM-5.1 side-by-side, then vote on the output you prefer.

GPT-5.6 Luna
✓ Preferred
GLM-5.1
Open in Playground
AI Model Comparison Table
Feature
OpenAI
GPT-5.6 Luna
Zhipu AI
GLM-5.1

FAQ

Common questions about GPT-5.6 Luna vs GLM-5.1.

Which is better, GPT-5.6 Luna or GLM-5.1?

GPT-5.6 Luna significantly outperforms across most benchmarks. GPT-5.6 Luna is made by OpenAI and GLM-5.1 is made by Zhipu 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 GLM-5.1 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%. GLM-5.1 scores Vending-Bench 2: 100.0%, AIME 2026: 95.3%, HMMT 2025: 94.0%, GPQA: 86.2%, IMO-AnswerBench: 83.8%.

Is GPT-5.6 Luna cheaper than GLM-5.1?

GPT-5.6 Luna is 1.4x cheaper for input tokens. GPT-5.6 Luna costs $1.00/M input and $6.00/M output via openai. GLM-5.1 costs $1.40/M input and $4.40/M output via friendli.

What are the context window sizes for GPT-5.6 Luna and GLM-5.1?

GPT-5.6 Luna supports 1.1M tokens and GLM-5.1 supports 200K 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 GLM-5.1?

Key differences include context window (1.1M vs 200K), input pricing ($1.00 vs $1.40/M), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.6 Luna and GLM-5.1?

GPT-5.6 Luna is developed by OpenAI and GLM-5.1 is developed by Zhipu AI.

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