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Claude Opus 5.5 vs Hy4 preview

Claude Opus 5.5 leads the LLM Stats Score 59.7 to 50.4.

Anthropic · Tencent · Updated for 2026

Which is better?

Claude Opus 5.5 leads the overall LLM Stats Score 59.7 to 50.4, ranking #1 overall.

In the 9 individual benchmarks reported for both models, Claude Opus 5.5 wins 9; 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 Claude Opus 5.5

  • overall performance matters — it scores 59.7 and ranks #1 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 9 of 9 exact shared results
  • you want the most recent training data — it shipped Sep 2026

Choose Hy4 preview

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

At a glance

The differences that matter most.

Claude Opus 5.5
Anthropic
Hy4 preview
Tencent
Core performance indexes
LLM Stats Score
59.7
#1
50.4
#15
Reasoning
57.8
#1
50.2
#11
Coding
51.7
#1
38.8
#16
Agents
44.5
#2
35.9
#18
Cost, coverage & limits
Benchmark wins
9 of 9
0 of 9
Input price
$4.00 / M
— / M
Output price
$20.00 / M
— / M
Context window
1,000,000
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

2 shared
Index
Claude Opus 5.5
Hy4 preview
Math
42.5#5
40.3#14
Tool use
32.9#2
27.7#19
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

31 reported for Claude Opus 5.5 · 32 for Hy4 preview

9 shared

Claude Opus 5.5 outperforms in 9 benchmarks (ArXivMath, AutomationBench, BioMysteryBench, Humanity's Last Exam (no tools, text-only), Humanity's Last Exam (with tools, text-only), OfficeQA Pro, Program Bench, SWE-bench Multilingual, SWE-Bench Pro), while Hy4 preview is better at 0 benchmarks.

Claude Opus 5.5 significantly outperforms across most benchmarks.

Wed Sep 23 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only Claude Opus 5.5 specifies input context (1,000,000 tokens). Only Claude Opus 5.5 specifies output context (128,000 tokens).

Anthropic
Claude Opus 5.5
Input1,000,000 tokens
Output128,000 tokens
Tencent
Hy4 preview
Input- tokens
Output- tokens
Wed Sep 23 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Opus 5.5 supports multimodal inputs, whereas Hy4 preview does not.

Claude Opus 5.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Opus 5.5

Text
Images
Audio
Video

Hy4 preview

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Opus 5.5 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.

Claude Opus 5.5

Proprietary

Closed source

Hy4 preview

Apache 2.0

Open weights

Release Timeline

When each model was launched

Claude Opus 5.5 was released on 2026-09-22, while Hy4 preview was released on 2026-08-28.

Claude Opus 5.5 is 1 month newer than Hy4 preview.

Claude Opus 5.5

Sep 22, 2026

0 days ago

3w newer
Hy4 preview

Aug 28, 2026

3 weeks ago

Knowledge Cutoff

When training data ends

Claude Opus 5.5 has a documented knowledge cutoff of 2026-06-01, while Hy4 preview's cutoff date is not specified.

We can confirm Claude Opus 5.5's training data extends to 2026-06-01, but cannot make a direct comparison without Hy4 preview's cutoff date.

Claude Opus 5.5

Jun 2026

Hy4 preview

—

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Opus 5.5 and Hy4 preview side-by-side, then vote on the output you prefer.

Claude Opus 5.5
✓ Preferred
Hy4 preview
Open in Playground

FAQ

Common questions about Claude Opus 5.5 vs Hy4 preview.

Which is better, Claude Opus 5.5 or Hy4 preview?

Claude Opus 5.5 leads the LLM Stats Score 59.7 to 50.4. Claude Opus 5.5 is made by Anthropic 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 Claude Opus 5.5 compare to Hy4 preview in benchmarks?

Claude Opus 5.5 scores BenchCAD (with Python tool): 96.2%, Global-MMLU: 94.3%, SWE-bench Multilingual: 93.9%, MILU: 93.1%, ArXivMath: 91.2%. 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 Claude Opus 5.5 and Hy4 preview?

Claude Opus 5.5 supports 1.0M 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 Claude Opus 5.5 and Hy4 preview?

Key differences include LLM Stats Score (59.7 vs 50.4), multimodal support (yes vs no), licensing (Proprietary vs Apache 2.0). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5.5 and Hy4 preview?

Claude Opus 5.5 is developed by Anthropic and Hy4 preview is developed by Tencent.

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