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Grok-4 Heavy vs Hy4 preview

Hy4 preview leads the LLM Stats Score 51.1 to 40.9.

xAI · Tencent · Updated for 2026

Which is better?

Hy4 preview leads the overall LLM Stats Score 51.1 to 40.9, ranking #14 overall.

In the 1 individual benchmarks reported for both models, Hy4 preview wins 1; 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 Grok-4 Heavy

  • you are already invested in the xAI ecosystem

Choose Hy4 preview

  • overall performance matters — it scores 51.1 and ranks #14 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Core performance indexes
40.9
#50
51.1
#14
39.2
#53
50.7
#11
17.9
#108
39.8
#12
Cost, coverage & limits
Benchmark wins
0 of 1
1 of 1
Input price
— / M
— / M
Output price
— / M
— / M
Context window

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Grok-4 Heavy
Hy4 preview
41.4#6
39.4#17
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

6 reported for Grok-4 Heavy · 32 for Hy4 preview

1 shared

Grok-4 Heavy outperforms in 0 benchmarks, while Hy4 preview is better at 1 benchmark (GPQA).

Hy4 preview significantly outperforms across most benchmarks.

Fri Sep 04 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Input capabilities

Documented input modalities across available providers

Grok-4 Heavy supports multimodal inputs, whereas Hy4 preview does not.

Grok-4 Heavy can handle both text and other forms of data like images, making it suitable for multimodal applications.

Grok-4 Heavy

Text
Images
Audio
Video

Hy4 preview

Text
Images
Audio
Video

License

Usage and distribution terms

Grok-4 Heavy 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.

Grok-4 Heavy

Proprietary

Closed source

Hy4 preview

Apache 2.0

Open weights

Release Timeline

When each model was launched

Hy4 preview was released on 2026-08-28, while Grok-4 Heavy's release date is not specified.

We can confirm Hy4 preview's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.

Grok-4 Heavy

Hy4 preview

Aug 28, 2026

1 weeks ago

Knowledge Cutoff

When training data ends

Grok-4 Heavy has a documented knowledge cutoff of 2024-12-31, while Hy4 preview's cutoff date is not specified.

We can confirm Grok-4 Heavy's training data extends to 2024-12-31, but cannot make a direct comparison without Hy4 preview's cutoff date.

Grok-4 Heavy

Dec 2024

Hy4 preview

Outputs Comparison

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Judge for yourself.

Run your own prompts against Grok-4 Heavy and Hy4 preview side-by-side, then vote on the output you prefer.

Grok-4 Heavy
✓ Preferred
Hy4 preview
Open in Playground

FAQ

Common questions about Grok-4 Heavy vs Hy4 preview.

Which is better, Grok-4 Heavy or Hy4 preview?

Hy4 preview leads the LLM Stats Score 51.1 to 40.9. Grok-4 Heavy is made by xAI 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 Grok-4 Heavy compare to Hy4 preview in benchmarks?

Grok-4 Heavy scores AIME 2025: 100.0%, HMMT25: 96.7%, GPQA: 88.4%, LiveCodeBench: 79.4%, USAMO25: 61.9%. 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 main differences between Grok-4 Heavy and Hy4 preview?

Key differences include LLM Stats Score (40.9 vs 51.1), multimodal support (yes vs no), licensing (Proprietary vs Apache 2.0). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok-4 Heavy and Hy4 preview?

Grok-4 Heavy is developed by xAI and Hy4 preview is developed by Tencent.