Anthropic Claude 4.0 Sonnet vs Anthropic Claude 3.5 Sonnet v2

Detailed comparison for LLMs

AnthropicAnthropic

On Guardion's LLM vulnerability Benchmark, Anthropic Claude 3.5 Sonnet v2 is the more secure of the two: Claude 4.0 Sonnet scores 13.6% and Claude 3.5 Sonnet v2 scores 4.4% on attack success rate (ASR) (lower is better).

Head-to-Head Overview

Claude 3.5 Sonnet v2 is the overall winner in this comparison!

Attack Success Rate (lower is safer)

ASR for Anthropic Claude 4.0 Sonnet vs Anthropic Claude 3.5 Sonnet v2. Green marks the safer model on each metric.

Overall (ASR)

Claude 4.0 Sonnet
13.6%
Claude 3.5 Sonnet v2
4.4%

TAP Attack Method (ASR)

Claude 4.0 Sonnet
22.0%
Claude 3.5 Sonnet v2
8.8%

Crescendo Attack Method (ASR)

Claude 4.0 Sonnet
14.8%
Claude 3.5 Sonnet v2
3.8%

Zero-Shot (ASR)

Claude 4.0 Sonnet
4.1%
Claude 3.5 Sonnet v2
0.5%

Key Highlights

  • Anthropic Claude 3.5 Sonnet v2 has a lower Overall (ASR).
  • Anthropic Claude 3.5 Sonnet v2 has a lower TAP Attack Method (ASR).
  • Anthropic Claude 3.5 Sonnet v2 has a lower Crescendo Attack Method (ASR).
  • Anthropic Claude 3.5 Sonnet v2 has a lower Zero-Shot (ASR).

Security Profile

Outward is better on every axis.

OverallTAPCrescendoZero-Shot
Claude 4.0 Sonnet
Claude 3.5 Sonnet v2
Full security profile
Anthropic Claude 4.0 Sonnet
Full security profile
Anthropic Claude 3.5 Sonnet v2

Frequently asked questions

Is Anthropic Claude 4.0 Sonnet or Anthropic Claude 3.5 Sonnet v2 more secure?

On Guardion's LLM vulnerability Benchmark, Anthropic Claude 3.5 Sonnet v2 is the more secure of the two: Claude 4.0 Sonnet scores 13.6% and Claude 3.5 Sonnet v2 scores 4.4% on attack success rate (ASR) (lower is better).

What is the attack success rate (ASR) of Claude 4.0 Sonnet vs Claude 3.5 Sonnet v2?

Claude 4.0 Sonnet has a 13.6% ASR and Claude 3.5 Sonnet v2 has a 4.4% ASR — the share of adversarial prompts that succeed across zero-shot, TAP, and Crescendo attacks. Lower is safer.

How were Claude 4.0 Sonnet and Claude 3.5 Sonnet v2 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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