Anthropic Claude Haiku 4.5 vs Anthropic Claude Sonnet 4.5

Detailed comparison for LLMs

AnthropicAnthropic

On Guardion's LLM vulnerability Benchmark, Anthropic Claude Sonnet 4.5 is the more secure of the two: Claude Haiku 4.5 scores 5.2% and Claude Sonnet 4.5 scores 4.2% 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 Haiku 4.5 vs Anthropic Claude Sonnet 4.5. Green marks the safer model on each metric. Only the overall score is available for estimated models.

Overall (ASR)

Claude Haiku 4.5
5.2%
Claude Sonnet 4.5
4.2%

TAP Attack Method (ASR)

Claude Haiku 4.5
100.0%
Claude Sonnet 4.5
100.0%

Crescendo Attack Method (ASR)

Claude Haiku 4.5
100.0%
Claude Sonnet 4.5
100.0%

Zero-Shot (ASR)

Claude Haiku 4.5
100.0%
Claude Sonnet 4.5
100.0%

Key Highlights

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

Security Profile

Outward is better on every axis.

OverallTAPCrescendoZero-Shot
Claude Haiku 4.5
Claude Sonnet 4.5
Full security profile
Anthropic Claude Haiku 4.5
Full security profile
Anthropic Claude Sonnet 4.5

Frequently asked questions

Is Anthropic Claude Haiku 4.5 or Anthropic Claude Sonnet 4.5 more secure?

On Guardion's LLM vulnerability Benchmark, Anthropic Claude Sonnet 4.5 is the more secure of the two: Claude Haiku 4.5 scores 5.2% and Claude Sonnet 4.5 scores 4.2% 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 Haiku 4.5 vs Claude Sonnet 4.5?

Claude Haiku 4.5 has a 5.2% ASR and Claude Sonnet 4.5 has a 4.2% ASR — the share of adversarial prompts that succeed across zero-shot, TAP, and Crescendo attacks. Lower is safer.

How were Claude Haiku 4.5 and Claude Sonnet 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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