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GPT-5.6 Luna vs Hy4 preview

Hy4 preview leads the LLM Stats Score 51.0 to 45.1.

OpenAI · Tencent · Updated for 2026

Which is better?

Hy4 preview leads the overall LLM Stats Score 51.0 to 45.1, ranking #14 overall.

In the 7 individual benchmarks reported for both models, Hy4 preview wins 5; this is a narrower head-to-head signal than the composite indexes.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose GPT-5.6 Luna

  • you want predictable pricing at $0.20/M input and $1.20/M output

Choose Hy4 preview

  • overall performance matters — it scores 51.0 and ranks #14 on LLM Stats
  • your work emphasizes reasoning and agents — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 5 of 7 exact shared results
  • you want the most recent training data — it shipped Aug 2026
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Core performance indexes
45.1
#32
51.0
#14
44.2
#36
50.8
#10
36.3
#21
39.7
#14
31.6
#29
36.7
#16
Cost, coverage & limits
Benchmark wins
2 of 7
5 of 7
Input price
$0.20 / M
— / M
Output price
$1.20 / M
— / M
Context window
1,050,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

2 shared
Index
GPT-5.6 Luna
Hy4 preview
28.8#90
41.0#11
25.8#33
30.9#14
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

45 reported for GPT-5.6 Luna · 32 for Hy4 preview

7 shared

GPT-5.6 Luna outperforms in 2 benchmarks (Agents' Last Exam, DeepSWE), while Hy4 preview is better at 4 benchmarks (AutomationBench, SWE-Bench Pro, Terminal-Bench 2.1, Toolathlon).

Hy4 preview has a slight edge in benchmark performance.

Sun Sep 20 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

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
Tencent
Hy4 preview
Input- tokens
Output- tokens
Sun Sep 20 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

GPT-5.6 Luna supports multimodal inputs, whereas Hy4 preview 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

Hy4 preview

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-5.6 Luna is licensed under a proprietary license, while Hy4 preview uses Apache 2.0.

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

GPT-5.6 Luna

Proprietary

Closed source

Hy4 preview

Apache 2.0

Open weights

Release Timeline

When each model was launched

GPT-5.6 Luna was released on 2026-07-09, while Hy4 preview was released on 2026-08-28.

Hy4 preview is 2 months newer than GPT-5.6 Luna.

GPT-5.6 Luna

Jul 9, 2026

2 months ago

Hy4 preview

Aug 28, 2026

3 weeks ago

1mo newer

Knowledge Cutoff

When training data ends

GPT-5.6 Luna has a documented knowledge cutoff of 2026-02-16, while Hy4 preview'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 Hy4 preview's cutoff date.

GPT-5.6 Luna

Feb 2026

Hy4 preview

Outputs Comparison

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Judge for yourself.

Run your own prompts against GPT-5.6 Luna and Hy4 preview side-by-side, then vote on the output you prefer.

GPT-5.6 Luna
✓ Preferred
Hy4 preview
Open in Playground

FAQ

Common questions about GPT-5.6 Luna vs Hy4 preview.

Which is better, GPT-5.6 Luna or Hy4 preview?

Hy4 preview leads the LLM Stats Score 51.0 to 45.1. GPT-5.6 Luna is made by OpenAI and Hy4 preview is made by Tencent. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GPT-5.6 Luna compare to Hy4 preview 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%. Hy4 preview scores GPQA: 92.3%, Terminal-Bench 2.1: 85.4%, WideSearch: 83.9%, MCP Atlas: 83.7%, SWE-bench Multilingual: 82.9%.

What are the context window sizes for GPT-5.6 Luna and Hy4 preview?

GPT-5.6 Luna supports 1.1M tokens and Hy4 preview 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 Hy4 preview?

Key differences include LLM Stats Score (45.1 vs 51.0), multimodal support (yes vs no), licensing (Proprietary vs Apache 2.0). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.6 Luna and Hy4 preview?

GPT-5.6 Luna is developed by OpenAI and Hy4 preview is developed by Tencent.