Model Comparison
GLM-4.6 vs GPT-5.6 LunaWhich is better in 2026?
GPT-5.6 Luna significantly outperforms across most benchmarks. GLM-4.6 is 2.5x cheaper per token.
Verdict: GLM-4.6 vs GPT-5.6 Luna — which is better?
GLM-4.6 (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-4.6 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.
On price, GLM-4.6 is roughly 2.5x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
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 GLM-4.6 if…
- cost matters — it's about 2.5x cheaper per token
- 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 process long inputs — it offers a 1,050,000 token context window
- you want the most recent training data — it shipped Jul 2026
Performance Benchmarks
Comparative analysis across standard metrics
GLM-4.6 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.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, GLM-4.6 ($0.55/1M tokens) is 1.8x cheaper than GPT-5.6 Luna ($1.00/1M tokens).
For output processing, GLM-4.6 ($2.00/1M tokens) is 3.0x cheaper than GPT-5.6 Luna ($6.00/1M tokens).
In conclusion, GPT-5.6 Luna is more expensive than GLM-4.6.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.6 Luna accepts 1,050,000 input tokens compared to GLM-4.6's 131,072 tokens. GLM-4.6 can generate longer responses up to 131,072 tokens, while GPT-5.6 Luna is limited to 128,000 tokens.
Input Capabilities
Supported data types and modalities
Both GLM-4.6 and GPT-5.6 Luna support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GLM-4.6
GPT-5.6 Luna
License
Usage and distribution terms
GLM-4.6 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.
MIT
Open weights
Proprietary
Closed source
Release Timeline
When each model was launched
GLM-4.6 was released on 2025-09-30, while GPT-5.6 Luna was released on 2026-07-09.
GPT-5.6 Luna is 9 months newer than GLM-4.6.
Sep 30, 2025
9 months ago
Jul 9, 2026
2 weeks ago
9mo newerKnowledge Cutoff
When training data ends
GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while GLM-4.6'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-4.6's cutoff date.
—
Feb 2026
Provider Availability
GLM-4.6 is available from Fireworks, DeepInfra. GPT-5.6 Luna is available from OpenAI.
GLM-4.6
GPT-5.6 Luna
Outputs Comparison
Key Takeaways
GLM-4.6
View detailsZhipu AI
GPT-5.6 Luna
View detailsOpenAI
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against GLM-4.6 and GPT-5.6 Luna side-by-side, then vote on the output you prefer.
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FAQ
Common questions about GLM-4.6 vs GPT-5.6 Luna.