Model Comparison

Nemotron 3 Ultra (550B A55B) vs GPT-5.5 ProWhich is better in 2026?

GPT-5.5 Pro significantly outperforms across most benchmarks.

Verdict: Nemotron 3 Ultra (550B A55B) vs GPT-5.5 Pro — which is better?

Nemotron 3 Ultra (550B A55B) (by NVIDIA) and GPT-5.5 Pro (by OpenAI) 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.

Nemotron 3 Ultra (550B A55B) outperforms in 0 benchmarks, while GPT-5.5 Pro is better at 2 benchmarks (BrowseComp, Humanity's Last Exam). GPT-5.5 Pro significantly outperforms across most benchmarks.

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

Choose GPT-5.5 Pro if…

  • you want the strongest raw capability — it leads on 2 of 2 shared benchmarks

Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Nemotron 3 Ultra (550B A55B) outperforms in 0 benchmarks, while GPT-5.5 Pro is better at 2 benchmarks (BrowseComp, Humanity's Last Exam).

GPT-5.5 Pro significantly outperforms across most benchmarks.

Fri Jul 17 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only GPT-5.5 Pro specifies input context (1,050,000 tokens). Only GPT-5.5 Pro specifies output context (128,000 tokens).

NVIDIA
Nemotron 3 Ultra (550B A55B)
Input- tokens
Output- tokens
OpenAI
GPT-5.5 Pro
Input1,050,000 tokens
Output128,000 tokens
Fri Jul 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-5.5 Pro supports multimodal inputs, whereas Nemotron 3 Ultra (550B A55B) does not.

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

Nemotron 3 Ultra (550B A55B)

Text
Images
Audio
Video

GPT-5.5 Pro

Text
Images
Audio
Video

License

Usage and distribution terms

Nemotron 3 Ultra (550B A55B) is licensed under OpenMDW License v1.1, while GPT-5.5 Pro uses a proprietary license.

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

Nemotron 3 Ultra (550B A55B)

OpenMDW License v1.1

Open weights

GPT-5.5 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

Nemotron 3 Ultra (550B A55B) was released on 2026-06-04, while GPT-5.5 Pro was released on 2026-04-23.

Nemotron 3 Ultra (550B A55B) is 1 month newer than GPT-5.5 Pro.

Nemotron 3 Ultra (550B A55B)

Jun 4, 2026

1 months ago

1mo newer
GPT-5.5 Pro

Apr 23, 2026

2 months ago

Knowledge Cutoff

When training data ends

Nemotron 3 Ultra (550B A55B) has a knowledge cutoff of 2025-09-30, while GPT-5.5 Pro has a cutoff of 2025-12-01.

GPT-5.5 Pro has more recent training data (up to 2025-12-01), making it potentially better informed about events through that date compared to Nemotron 3 Ultra (550B A55B) (2025-09-30).

Nemotron 3 Ultra (550B A55B)

Sep 2025

GPT-5.5 Pro

Dec 2025

3 mo newer

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

NVIDIA
Has open weights
OpenAI
Larger context window (1,050,000 tokens)
Supports multimodal inputs
Higher BrowseComp score (90.1% vs 44.4%)
Higher Humanity's Last Exam score (57.2% vs 37.4%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Nemotron 3 Ultra (550B A55B) and GPT-5.5 Pro side-by-side, then vote on the output you prefer.

Nemotron 3 Ultra (550B A55B)
✓ Preferred
GPT-5.5 Pro
Open in Playground
AI Model Comparison Table
Feature
NVIDIA
Nemotron 3 Ultra (550B A55B)
OpenAI
GPT-5.5 Pro

FAQ

Common questions about Nemotron 3 Ultra (550B A55B) vs GPT-5.5 Pro.

Which is better, Nemotron 3 Ultra (550B A55B) or GPT-5.5 Pro?

GPT-5.5 Pro significantly outperforms across most benchmarks. Nemotron 3 Ultra (550B A55B) is made by NVIDIA and GPT-5.5 Pro is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Nemotron 3 Ultra (550B A55B) compare to GPT-5.5 Pro in benchmarks?

Nemotron 3 Ultra (550B A55B) scores RULER: 94.7%, IMO-AnswerBench: 92.3%, PinchBench: 90.0%, LiveCodeBench v6: 89.0%, GPQA: 87.0%. GPT-5.5 Pro scores BrowseComp: 90.1%, GDPval-MM: 82.3%, Humanity's Last Exam: 57.2%, FrontierMath: 39.6%, GeneBench: 33.2%.

What are the context window sizes for Nemotron 3 Ultra (550B A55B) and GPT-5.5 Pro?

Nemotron 3 Ultra (550B A55B) supports an unknown number of tokens and GPT-5.5 Pro supports 1.1M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Nemotron 3 Ultra (550B A55B) and GPT-5.5 Pro?

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

Who makes Nemotron 3 Ultra (550B A55B) and GPT-5.5 Pro?

Nemotron 3 Ultra (550B A55B) is developed by NVIDIA and GPT-5.5 Pro is developed by OpenAI.

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