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GPT-5.1 Codex High vs Hy4 preview

Hy4 preview leads the LLM Stats Score 50.7 to 29.4.

OpenAI · Tencent · Updated for 2026

Which is better?

Hy4 preview leads the overall LLM Stats Score 50.7 to 29.4, ranking #15 overall.

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

Choose GPT-5.1 Codex High

  • you want predictable pricing at $1.25/M input and $10.00/M output

Choose Hy4 preview

  • overall performance matters — it scores 50.7 and ranks #15 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • 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
29.4
#132
50.7
#15
29.2
#125
50.5
#10
Cost, coverage & limits
Benchmark wins
Input price
$1.25 / M
— / M
Output price
$10.00 / M
— / M
Context window
400,000

Individual benchmarks

1 reported for GPT-5.1 Codex High · 32 for Hy4 preview

No common benchmarks found

GPT-5.1 Codex High and Hy4 previewdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only GPT-5.1 Codex High specifies input context (400,000 tokens). Only GPT-5.1 Codex High specifies output context (128,000 tokens).

OpenAI
GPT-5.1 Codex High
Input400,000 tokens
Output128,000 tokens
Tencent
Hy4 preview
Input- tokens
Output- tokens
Tue Sep 22 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

GPT-5.1 Codex High supports multimodal inputs, whereas Hy4 preview does not.

GPT-5.1 Codex High can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-5.1 Codex High

Text
Images
Audio
Video

Hy4 preview

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-5.1 Codex High 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-5.1 Codex High

Proprietary

Closed source

Hy4 preview

Apache 2.0

Open weights

Release Timeline

When each model was launched

GPT-5.1 Codex High was released on 2025-11-12, while Hy4 preview was released on 2026-08-28.

Hy4 preview is 10 months newer than GPT-5.1 Codex High.

GPT-5.1 Codex High

Nov 12, 2025

10 months ago

Hy4 preview

Aug 28, 2026

3 weeks ago

9mo newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against GPT-5.1 Codex High and Hy4 preview side-by-side, then vote on the output you prefer.

GPT-5.1 Codex High
✓ Preferred
Hy4 preview
Open in Playground

FAQ

Common questions about GPT-5.1 Codex High vs Hy4 preview.

Which is better, GPT-5.1 Codex High or Hy4 preview?

Hy4 preview leads the LLM Stats Score 50.7 to 29.4. GPT-5.1 Codex High 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-5.1 Codex High compare to Hy4 preview in benchmarks?

GPT-5.1 Codex High scores AIME 2025: 96.7%. 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-5.1 Codex High and Hy4 preview?

GPT-5.1 Codex High supports 400K 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-5.1 Codex High and Hy4 preview?

Key differences include LLM Stats Score (29.4 vs 50.7), multimodal support (yes vs no), licensing (Proprietary vs Apache 2.0). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.1 Codex High and Hy4 preview?

GPT-5.1 Codex High is developed by OpenAI and Hy4 preview is developed by Tencent.