Anthropic Claude Sonnet 4.5 vs Amazon Nova Premier

Detailed comparison for LLMs

AnthropicAmazon

On Guardion's LLM vulnerability Benchmark, Anthropic Claude Sonnet 4.5 is the more secure of the two: Claude Sonnet 4.5 scores 4.2% and Nova Premier scores 20.0% 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 Sonnet 4.5 is the overall winner in this comparison!

Attack Success Rate (lower is safer)

ASR for Anthropic Claude Sonnet 4.5 vs Amazon Nova Premier. Green marks the safer model on each metric. Only the overall score is available for estimated models.

Overall (ASR)

Claude Sonnet 4.5
4.2%
Nova Premier
20.0%

TAP Attack Method (ASR)

Claude Sonnet 4.5
100.0%
Nova Premier

Crescendo Attack Method (ASR)

Claude Sonnet 4.5
100.0%
Nova Premier

Zero-Shot (ASR)

Claude Sonnet 4.5
100.0%
Nova Premier

Key Highlights

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

Security Profile

Outward is better on every axis.

OverallTAPCrescendoZero-Shot
Claude Sonnet 4.5
Nova Premier
Full security profile
Anthropic Claude Sonnet 4.5
Full security profile
Amazon Nova Premier

Frequently asked questions

Is Anthropic Claude Sonnet 4.5 or Amazon Nova Premier more secure?

On Guardion's LLM vulnerability Benchmark, Anthropic Claude Sonnet 4.5 is the more secure of the two: Claude Sonnet 4.5 scores 4.2% and Nova Premier scores 20.0% 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 Sonnet 4.5 vs Nova Premier?

Claude Sonnet 4.5 has a 4.2% ASR and Nova Premier has a 20.0% ASR — the share of adversarial prompts that succeed across zero-shot, TAP, and Crescendo attacks. Lower is safer.

How were Claude Sonnet 4.5 and Nova Premier 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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