Amazon Nova Pro vs Anthropic Claude Opus 4.5

Detailed comparison for LLMs

AmazonAnthropic

On Guardion's LLM vulnerability Benchmark, Anthropic Claude Opus 4.5 is the more secure of the two: Nova Pro scores 24.0% and Claude Opus 4.5 scores 3.4% 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 Amazon Nova Pro vs Anthropic Claude Opus 4.5. Green marks the safer model on each metric. Only the overall score is available for estimated models.

Overall (ASR)

Nova Pro
24.0%
Claude Opus 4.5
3.4%

TAP Attack Method (ASR)

Nova Pro
100.0%
Claude Opus 4.5
100.0%

Crescendo Attack Method (ASR)

Nova Pro
100.0%
Claude Opus 4.5
100.0%

Zero-Shot (ASR)

Nova Pro
100.0%
Claude Opus 4.5
100.0%

Key Highlights

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

Security Profile

Outward is better on every axis.

OverallTAPCrescendoZero-Shot
Nova Pro
Claude Opus 4.5
Full security profile
Amazon Nova Pro
Full security profile
Anthropic Claude Opus 4.5

Frequently asked questions

Is Amazon Nova Pro or Anthropic Claude Opus 4.5 more secure?

On Guardion's LLM vulnerability Benchmark, Anthropic Claude Opus 4.5 is the more secure of the two: Nova Pro scores 24.0% and Claude Opus 4.5 scores 3.4% 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 Nova Pro vs Claude Opus 4.5?

Nova Pro has a 24.0% ASR and Claude Opus 4.5 has a 3.4% ASR — the share of adversarial prompts that succeed across zero-shot, TAP, and Crescendo attacks. Lower is safer.

How were Nova Pro and Claude Opus 4.5 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.

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