OpenAI GPT-5.2 Pro vs Anthropic Claude Opus 4.5

Detailed comparison for LLMs

OpenAIAnthropic

On Guardion's LLM vulnerability Benchmark, Anthropic Claude Opus 4.5 is the more secure of the two: GPT-5.2 Pro scores 3.8% 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 OpenAI GPT-5.2 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)

GPT-5.2 Pro
3.8%
Claude Opus 4.5
3.4%

TAP Attack Method (ASR)

GPT-5.2 Pro
100.0%
Claude Opus 4.5
100.0%

Crescendo Attack Method (ASR)

GPT-5.2 Pro
100.0%
Claude Opus 4.5
100.0%

Zero-Shot (ASR)

GPT-5.2 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
GPT-5.2 Pro
Claude Opus 4.5
Full security profile
OpenAI GPT-5.2 Pro
Full security profile
Anthropic Claude Opus 4.5

Frequently asked questions

Is OpenAI GPT-5.2 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: GPT-5.2 Pro scores 3.8% 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 GPT-5.2 Pro vs Claude Opus 4.5?

GPT-5.2 Pro has a 3.8% 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 GPT-5.2 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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