OpenAI o3-mini vs Anthropic Claude 4.0 Sonnet

Detailed comparison for LLMs

OpenAIAnthropic

On Guardion's LLM vulnerability Benchmark, OpenAI o3-mini is the more secure of the two: o3-mini scores 9.0% 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

o3-mini is the overall winner in this comparison!

Attack Success Rate (lower is safer)

ASR for OpenAI o3-mini 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)

o3-mini
9.0%
Claude 4.0 Sonnet
13.6%

TAP Attack Method (ASR)

o3-mini
100.0%
Claude 4.0 Sonnet
22.0%

Crescendo Attack Method (ASR)

o3-mini
100.0%
Claude 4.0 Sonnet
14.8%

Zero-Shot (ASR)

o3-mini
100.0%
Claude 4.0 Sonnet
4.1%

Key Highlights

  • OpenAI o3-mini 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.

OverallTAPCrescendoZero-Shot
o3-mini
Claude 4.0 Sonnet
Full security profile
OpenAI o3-mini
Full security profile
Anthropic Claude 4.0 Sonnet

Frequently asked questions

Is OpenAI o3-mini or Anthropic Claude 4.0 Sonnet more secure?

On Guardion's LLM vulnerability Benchmark, OpenAI o3-mini is the more secure of the two: o3-mini scores 9.0% 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 o3-mini vs Claude 4.0 Sonnet?

o3-mini has a 9.0% 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 o3-mini 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.

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