Anthropic Claude Haiku 4.5 vs Anthropic Claude 4.0 Sonnet
Detailed comparison for LLMs
On Guardion's LLM vulnerability Benchmark, Anthropic Claude Haiku 4.5 is the more secure of the two: Claude Haiku 4.5 scores 5.2% and Claude 4.0 Sonnet scores 13.6% 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 Haiku 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 4.0 Sonnet. Green marks the safer model on each metric. Only the overall score is available for estimated models.
Overall (ASR)
TAP Attack Method (ASR)
Crescendo Attack Method (ASR)
Zero-Shot (ASR)
Key Highlights
- Anthropic Claude Haiku 4.5 has a lower Overall (ASR).
- Anthropic Claude 4.0 Sonnet has a lower TAP Attack Method (ASR).
- Anthropic Claude 4.0 Sonnet has a lower Crescendo Attack Method (ASR).
- Anthropic Claude 4.0 Sonnet has a lower Zero-Shot (ASR).
Security Profile
Outward is better on every axis.
Frequently asked questions
Is Anthropic Claude Haiku 4.5 or Anthropic Claude 4.0 Sonnet more secure?
On Guardion's LLM vulnerability Benchmark, Anthropic Claude Haiku 4.5 is the more secure of the two: Claude Haiku 4.5 scores 5.2% and Claude 4.0 Sonnet scores 13.6% 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 4.0 Sonnet?
Claude Haiku 4.5 has a 5.2% ASR and Claude 4.0 Sonnet has a 13.6% 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 4.0 Sonnet 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.