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Claude Sonnet 5.5 vs DeepSeek R1 Zero

Claude Sonnet 5.5 leads the LLM Stats Score 51.5 to 16.0.

Anthropic · DeepSeek · Updated for 2026

Which is better?

Claude Sonnet 5.5 leads the overall LLM Stats Score 51.5 to 16.0, ranking #12 overall.

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

Choose Claude Sonnet 5.5

  • overall performance matters — it scores 51.5 and ranks #12 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you want the most recent training data — it shipped Sep 2026

Choose DeepSeek R1 Zero

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

At a glance

The differences that matter most.

Claude Sonnet 5.5
Anthropic
DeepSeek R1 Zero
DeepSeek
Core performance indexes
LLM Stats Score
51.5
#12
16.0
#233
Reasoning
49.7
#16
16.3
#223
Coding
42.6
#7
4.3
#216
Cost, coverage & limits
Benchmark wins
—
—
Input price
$2.00 / M
— / M
Output price
$10.00 / M
— / M
Context window
1,000,000
—

Individual benchmarks

8 reported for Claude Sonnet 5.5 · 4 for DeepSeek R1 Zero

No common benchmarks found

Claude Sonnet 5.5 and DeepSeek R1 Zerodon'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 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
DeepSeek
DeepSeek R1 Zero
Input- tokens
Output- tokens
Mon Sep 28 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Sonnet 5.5 supports multimodal inputs, whereas DeepSeek R1 Zero 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

DeepSeek R1 Zero

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Sonnet 5.5 is licensed under a proprietary license, while DeepSeek R1 Zero uses MIT.

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

Claude Sonnet 5.5

Proprietary

Closed source

DeepSeek R1 Zero

MIT

Open weights

Release Timeline

When each model was launched

Claude Sonnet 5.5 was released on 2026-09-28, while DeepSeek R1 Zero was released on 2025-01-20.

Claude Sonnet 5.5 is 21 months newer than DeepSeek R1 Zero.

Claude Sonnet 5.5

Sep 28, 2026

-1 days ago

1.7yr newer
DeepSeek R1 Zero

Jan 20, 2025

1.7 years ago

Knowledge Cutoff

When training data ends

Claude Sonnet 5.5 has a documented knowledge cutoff of 2026-06-01, while DeepSeek R1 Zero'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 DeepSeek R1 Zero's cutoff date.

Claude Sonnet 5.5

Jun 2026

DeepSeek R1 Zero

—

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Sonnet 5.5 and DeepSeek R1 Zero side-by-side, then vote on the output you prefer.

Claude Sonnet 5.5
✓ Preferred
DeepSeek R1 Zero
Open in Playground

FAQ

Common questions about Claude Sonnet 5.5 vs DeepSeek R1 Zero.

Which is better, Claude Sonnet 5.5 or DeepSeek R1 Zero?

Claude Sonnet 5.5 leads the LLM Stats Score 51.5 to 16.0. Claude Sonnet 5.5 is made by Anthropic and DeepSeek R1 Zero is made by DeepSeek. 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 DeepSeek R1 Zero in benchmarks?

Claude Sonnet 5.5 scores OSWorld 2.1 (partial): 80.1%, Terminal-Bench 4.0: 70.6%, Humanity's Last Exam (with tools): 64.5%, Chartography (no tools): 61.6%, GDPval-AA 2.1: 61.5%. DeepSeek R1 Zero scores MATH-500: 95.9%, AIME 2024: 86.7%, GPQA: 73.3%, LiveCodeBench: 50.0%.

What are the context window sizes for Claude Sonnet 5.5 and DeepSeek R1 Zero?

Claude Sonnet 5.5 supports 1.0M tokens and DeepSeek R1 Zero 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 DeepSeek R1 Zero?

Key differences include LLM Stats Score (51.5 vs 16.0), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Sonnet 5.5 and DeepSeek R1 Zero?

Claude Sonnet 5.5 is developed by Anthropic and DeepSeek R1 Zero is developed by DeepSeek.

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