Anthropic Claude Opus 4.5 vs NVIDIA Llama 3.1 Nemotron Ultra 253B v1

Detailed comparison for LLMs

AnthropicNVIDIA

On Guardion's LLM vulnerability Benchmark, Anthropic Claude Opus 4.5 is the more secure of the two: Claude Opus 4.5 scores 3.4% and Llama 3.1 Nemotron Ultra 253B v1 scores 40.0% on attack success rate (ASR) (lower is better). One or both scores are estimated from public safety evaluations pending a Guardion benchmark run.

Head-to-Head Overview

Claude Opus 4.5 is the overall winner in this comparison!

Attack Success Rate (lower is safer)

ASR for Anthropic Claude Opus 4.5 vs NVIDIA Llama 3.1 Nemotron Ultra 253B v1. Green marks the safer model on each metric. Only the overall score is available for estimated models.

Overall (ASR)

Claude Opus 4.5
3.4%
Llama 3.1 Nemotron Ultra 253B v1
40.0%

TAP Attack Method (ASR)

Claude Opus 4.5
100.0%
Llama 3.1 Nemotron Ultra 253B v1
100.0%

Crescendo Attack Method (ASR)

Claude Opus 4.5
100.0%
Llama 3.1 Nemotron Ultra 253B v1
100.0%

Zero-Shot (ASR)

Claude Opus 4.5
100.0%
Llama 3.1 Nemotron Ultra 253B v1
100.0%

Key Highlights

  • Anthropic Claude Opus 4.5 has a lower Overall (ASR).

Security Profile

Outward is better on every axis.

OverallTAPCrescendoZero-Shot
Claude Opus 4.5
Llama 3.1 Nemotron Ultra 253B v1
Full security profile
Anthropic Claude Opus 4.5
Full security profile
NVIDIA Llama 3.1 Nemotron Ultra 253B v1

Frequently asked questions

Is Anthropic Claude Opus 4.5 or NVIDIA Llama 3.1 Nemotron Ultra 253B v1 more secure?

On Guardion's LLM vulnerability Benchmark, Anthropic Claude Opus 4.5 is the more secure of the two: Claude Opus 4.5 scores 3.4% and Llama 3.1 Nemotron Ultra 253B v1 scores 40.0% on attack success rate (ASR) (lower is better). One or both scores are estimated from public safety evaluations pending a Guardion benchmark run.

What is the attack success rate (ASR) of Claude Opus 4.5 vs Llama 3.1 Nemotron Ultra 253B v1?

Claude Opus 4.5 has a 3.4% ASR and Llama 3.1 Nemotron Ultra 253B v1 has a 40.0% ASR — the share of adversarial prompts that succeed across zero-shot, TAP, and Crescendo attacks. Lower is safer.

How were Claude Opus 4.5 and Llama 3.1 Nemotron Ultra 253B v1 tested?

Both were red-teamed with the HarmBench framework across zero-shot, TAP (Tree of Attacks with Pruning), and Crescendo multi-turn attacks, scored by Attack Success Rate.

Related Comparisons