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Claude Sonnet 5.5 vs Hy4 preview

Claude Sonnet 5.5 leads the LLM Stats Score 58.7 to 49.9.

Anthropic · Tencent · Updated for 2026

Which is better?

Claude Sonnet 5.5 leads the overall LLM Stats Score 58.7 to 49.9, ranking #2 overall.

In the 8 individual benchmarks reported for both models, Claude Sonnet 5.5 wins 7; 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 Sonnet 5.5

  • overall performance matters — it scores 58.7 and ranks #2 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 7 of 8 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 Sonnet 5.5
Anthropic
Hy4 preview
Tencent
Core performance indexes
LLM Stats Score
58.7
#2
49.9
#20
Reasoning
57.2
#3
49.9
#14
Coding
48.3
#2
37.8
#21
Agents
43.2
#3
34.9
#22
Cost, coverage & limits
Benchmark wins
7 of 8
1 of 8
Input price
$2.00 / M
— / M
Output price
$10.00 / M
— / M
Context window
1,000,000
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

2 shared
Index
Claude Sonnet 5.5
Hy4 preview
Math
37.6#30
38.7#24
Tool use
35.4#2
28.0#22
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

47 reported for Claude Sonnet 5.5 · 32 for Hy4 preview

8 shared

Claude Sonnet 5.5 outperforms in 7 benchmarks (ArXivMath, AutomationBench, BioMysteryBench, Humanity's Last Exam (no tools, text-only), Program Bench, SWE-bench Multilingual, SWE-Bench Pro), while Hy4 preview is better at 1 benchmark (OfficeQA Pro).

Claude Sonnet 5.5 significantly outperforms across most benchmarks.

Sat Oct 17 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 Sonnet 5.5 specifies input context (1,000,000 tokens). Only Claude Sonnet 5.5 specifies output context (128,000 tokens).

Anthropic
Claude Sonnet 5.5
Input1,000,000 tokens
Output128,000 tokens
Tencent
Hy4 preview
Input- tokens
Output- tokens
Sat Oct 17 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

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

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

Claude Sonnet 5.5

Text
Images
Audio
Video

Hy4 preview

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Sonnet 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 Sonnet 5.5

Proprietary

Closed source

Hy4 preview

Apache 2.0

Open weights

Release Timeline

When each model was launched

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

Claude Sonnet 5.5 is 1 month newer than Hy4 preview.

Claude Sonnet 5.5

Sep 28, 2026

1 weeks ago

1mo newer
Hy4 preview

Aug 28, 2026

1 months ago

Knowledge Cutoff

When training data ends

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

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

Claude Sonnet 5.5

Jun 2026

Hy4 preview

—

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

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

Claude Sonnet 5.5
✓ Preferred
Hy4 preview
Open in Playground

FAQ

Common questions about Claude Sonnet 5.5 vs Hy4 preview.

Which is better, Claude Sonnet 5.5 or Hy4 preview?

Claude Sonnet 5.5 leads the LLM Stats Score 58.7 to 49.9. Claude Sonnet 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 Sonnet 5.5 compare to Hy4 preview in benchmarks?

Claude Sonnet 5.5 scores BenchCAD (with Python tool): 96.3%, ArXivMath (with tools): 95.2%, Global-MMLU: 92.1%, MILU: 91.6%, SWE-bench Multilingual: 90.3%. 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 Sonnet 5.5 and Hy4 preview?

Claude Sonnet 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 Sonnet 5.5 and Hy4 preview?

Key differences include LLM Stats Score (58.7 vs 49.9), multimodal support (yes vs no), licensing (Proprietary vs Apache 2.0). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Sonnet 5.5 and Hy4 preview?

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

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