Model Comparison

Claude Sonnet 4.5 vs Llama 3.1 Nemotron Ultra 253B v1Which is better in 2026?

Claude Sonnet 4.5 significantly outperforms across most benchmarks.

Verdict: Claude Sonnet 4.5 vs Llama 3.1 Nemotron Ultra 253B v1 — which is better?

Claude Sonnet 4.5 (by Anthropic) and Llama 3.1 Nemotron Ultra 253B v1 (by NVIDIA) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Claude Sonnet 4.5 outperforms in 2 benchmarks (AIME 2025, GPQA), while Llama 3.1 Nemotron Ultra 253B v1 is better at 0 benchmarks. Claude Sonnet 4.5 significantly outperforms across most benchmarks.

Choose Claude Sonnet 4.5 if…

  • you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
  • you want the most recent training data — it shipped Sep 2025

Choose Llama 3.1 Nemotron Ultra 253B v1 if…

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

Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Claude Sonnet 4.5 outperforms in 2 benchmarks (AIME 2025, GPQA), while Llama 3.1 Nemotron Ultra 253B v1 is better at 0 benchmarks.

Claude Sonnet 4.5 significantly outperforms across most benchmarks.

Sat Jun 27 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only Claude Sonnet 4.5 specifies input context (200,000 tokens). Only Claude Sonnet 4.5 specifies output context (64,000 tokens).

Anthropic
Claude Sonnet 4.5
Input200,000 tokens
Output64,000 tokens
NVIDIA
Llama 3.1 Nemotron Ultra 253B v1
Input- tokens
Output- tokens
Sat Jun 27 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude Sonnet 4.5 supports multimodal inputs, whereas Llama 3.1 Nemotron Ultra 253B v1 does not.

Claude Sonnet 4.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Sonnet 4.5

Text
Images
Audio
Video

Llama 3.1 Nemotron Ultra 253B v1

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Sonnet 4.5 is licensed under a proprietary license, while Llama 3.1 Nemotron Ultra 253B v1 uses Llama 3.1 Community License.

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

Claude Sonnet 4.5

Proprietary

Closed source

Llama 3.1 Nemotron Ultra 253B v1

Llama 3.1 Community License

Open weights

Release Timeline

When each model was launched

Claude Sonnet 4.5 was released on 2025-09-29, while Llama 3.1 Nemotron Ultra 253B v1 was released on 2025-04-07.

Claude Sonnet 4.5 is 6 months newer than Llama 3.1 Nemotron Ultra 253B v1.

Claude Sonnet 4.5

Sep 29, 2025

9 months ago

5mo newer
Llama 3.1 Nemotron Ultra 253B v1

Apr 7, 2025

1.2 years ago

Knowledge Cutoff

When training data ends

Claude Sonnet 4.5 has a knowledge cutoff of 2025-01-31, while Llama 3.1 Nemotron Ultra 253B v1 has a cutoff of 2023-12-01.

Claude Sonnet 4.5 has more recent training data (up to 2025-01-31), making it potentially better informed about events through that date compared to Llama 3.1 Nemotron Ultra 253B v1 (2023-12-01).

Claude Sonnet 4.5

Jan 2025

1.1 yr newer
Llama 3.1 Nemotron Ultra 253B v1

Dec 2023

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic
Larger context window (200,000 tokens)
Supports multimodal inputs
Higher AIME 2025 score (87.0% vs 72.5%)
Higher GPQA score (83.4% vs 76.0%)
NVIDIA
Has open weights

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Claude Sonnet 4.5 and Llama 3.1 Nemotron Ultra 253B v1 side-by-side, then vote on the output you prefer.

Claude Sonnet 4.5
✓ Preferred
Llama 3.1 Nemotron Ultra 253B v1
Open in Playground
AI Model Comparison Table
Feature
Anthropic
Claude Sonnet 4.5
NVIDIA
Llama 3.1 Nemotron Ultra 253B v1

FAQ

Common questions about Claude Sonnet 4.5 vs Llama 3.1 Nemotron Ultra 253B v1.

Which is better, Claude Sonnet 4.5 or Llama 3.1 Nemotron Ultra 253B v1?

Claude Sonnet 4.5 significantly outperforms across most benchmarks. Claude Sonnet 4.5 is made by Anthropic and Llama 3.1 Nemotron Ultra 253B v1 is made by NVIDIA. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Sonnet 4.5 compare to Llama 3.1 Nemotron Ultra 253B v1 in benchmarks?

Claude Sonnet 4.5 scores MMMLU: 89.1%, AIME 2025: 87.0%, TAU-bench Retail: 86.2%, GPQA: 83.4%, MMMUval: 77.8%. Llama 3.1 Nemotron Ultra 253B v1 scores MATH-500: 97.0%, IFEval: 89.5%, GPQA: 76.0%, BFCL v2: 74.1%, AIME 2025: 72.5%.

What are the context window sizes for Claude Sonnet 4.5 and Llama 3.1 Nemotron Ultra 253B v1?

Claude Sonnet 4.5 supports 200K tokens and Llama 3.1 Nemotron Ultra 253B v1 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 4.5 and Llama 3.1 Nemotron Ultra 253B v1?

Key differences include multimodal support (yes vs no), licensing (Proprietary vs Llama 3.1 Community License). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Sonnet 4.5 and Llama 3.1 Nemotron Ultra 253B v1?

Claude Sonnet 4.5 is developed by Anthropic and Llama 3.1 Nemotron Ultra 253B v1 is developed by NVIDIA.

Related comparisons