Model Comparison

Claude Opus 4.5 vs Nemotron 3 Ultra (550B A55B)Which is better in 2026?

Claude Opus 4.5 has a slight edge in benchmark performance.

Verdict: Claude Opus 4.5 vs Nemotron 3 Ultra (550B A55B) — which is better?

Claude Opus 4.5 (by Anthropic) and Nemotron 3 Ultra (550B A55B) (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 Opus 4.5 outperforms in 1 benchmarks (SWE-Bench Verified), while Nemotron 3 Ultra (550B A55B) is better at 0 benchmarks. Claude Opus 4.5 has a slight edge in benchmark performance.

Choose Claude Opus 4.5 if…

  • you want predictable pricing at $5.00/M input and $25.00/M output

Choose Nemotron 3 Ultra (550B A55B) if…

  • you want the most recent training data — it shipped Jun 2026
  • you need open weights you can self-host or fine-tune
Want to compare interactively?Try the playground

Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Claude Opus 4.5 outperforms in 1 benchmarks (SWE-Bench Verified), while Nemotron 3 Ultra (550B A55B) is better at 0 benchmarks.

Claude Opus 4.5 has a slight edge in benchmark performance.

Wed Jun 17 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

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

Anthropic
Claude Opus 4.5
Input200,000 tokens
Output64,000 tokens
NVIDIA
Nemotron 3 Ultra (550B A55B)
Input- tokens
Output- tokens
Wed Jun 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude Opus 4.5 supports multimodal inputs, whereas Nemotron 3 Ultra (550B A55B) does not.

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

Claude Opus 4.5

Text
Images
Audio
Video

Nemotron 3 Ultra (550B A55B)

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Opus 4.5 is licensed under a proprietary license, while Nemotron 3 Ultra (550B A55B) uses OpenMDW License v1.1.

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

Claude Opus 4.5

Proprietary

Closed source

Nemotron 3 Ultra (550B A55B)

OpenMDW License v1.1

Open weights

Release Timeline

When each model was launched

Claude Opus 4.5 was released on 2025-11-24, while Nemotron 3 Ultra (550B A55B) was released on 2026-06-04.

Nemotron 3 Ultra (550B A55B) is 6 months newer than Claude Opus 4.5.

Claude Opus 4.5

Nov 24, 2025

6 months ago

Nemotron 3 Ultra (550B A55B)

Jun 4, 2026

1 weeks ago

6mo newer

Knowledge Cutoff

When training data ends

Claude Opus 4.5 has a knowledge cutoff of 2025-03-31, while Nemotron 3 Ultra (550B A55B) has a cutoff of 2025-09-30.

Nemotron 3 Ultra (550B A55B) has more recent training data (up to 2025-09-30), making it potentially better informed about events through that date compared to Claude Opus 4.5 (2025-03-31).

Claude Opus 4.5

Mar 2025

Nemotron 3 Ultra (550B A55B)

Sep 2025

6 mo newer

Outputs Comparison

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Key Takeaways

Anthropic
Larger context window (200,000 tokens)
Supports multimodal inputs
Higher SWE-Bench Verified score (80.9% vs 70.7%)
NVIDIA
Has open weights

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Opus 4.5
NVIDIA
Nemotron 3 Ultra (550B A55B)

FAQ

Common questions about Claude Opus 4.5 vs Nemotron 3 Ultra (550B A55B).

Which is better, Claude Opus 4.5 or Nemotron 3 Ultra (550B A55B)?

Claude Opus 4.5 has a slight edge in benchmark performance. Claude Opus 4.5 is made by Anthropic and Nemotron 3 Ultra (550B A55B) is made by NVIDIA. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Opus 4.5 compare to Nemotron 3 Ultra (550B A55B) in benchmarks?

Claude Opus 4.5 scores Tau2 Telecom: 98.2%, MMMLU: 90.8%, Tau2 Retail: 88.9%, GPQA: 87.0%, SWE-Bench Verified: 80.9%. Nemotron 3 Ultra (550B A55B) scores RULER: 94.7%, IMO-AnswerBench: 92.3%, PinchBench: 90.0%, LiveCodeBench v6: 89.0%, GPQA: 87.0%.

What are the context window sizes for Claude Opus 4.5 and Nemotron 3 Ultra (550B A55B)?

Claude Opus 4.5 supports 200K tokens and Nemotron 3 Ultra (550B A55B) 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 4.5 and Nemotron 3 Ultra (550B A55B)?

Key differences include multimodal support (yes vs no), licensing (Proprietary vs OpenMDW License v1.1). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.5 and Nemotron 3 Ultra (550B A55B)?

Claude Opus 4.5 is developed by Anthropic and Nemotron 3 Ultra (550B A55B) is developed by NVIDIA.

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