Anthropic Claude Haiku 4.5 vs Google Gemini 2.0 Flash

Detailed comparison for LLMs

AnthropicGoogle

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 Gemini 2.0 Flash scores 33.6% 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 Google Gemini 2.0 Flash. 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%
Gemini 2.0 Flash
33.6%

TAP Attack Method (ASR)

Claude Haiku 4.5
100.0%
Gemini 2.0 Flash
67.6%

Crescendo Attack Method (ASR)

Claude Haiku 4.5
100.0%
Gemini 2.0 Flash
30.4%

Zero-Shot (ASR)

Claude Haiku 4.5
100.0%
Gemini 2.0 Flash
2.8%

Key Highlights

  • Anthropic Claude Haiku 4.5 has a lower Overall (ASR).
  • Google Gemini 2.0 Flash has a lower TAP Attack Method (ASR).
  • Google Gemini 2.0 Flash has a lower Crescendo Attack Method (ASR).
  • Google Gemini 2.0 Flash has a lower Zero-Shot (ASR).

Security Profile

Outward is better on every axis.

OverallTAPCrescendoZero-Shot
Claude Haiku 4.5
Gemini 2.0 Flash
Full security profile
Anthropic Claude Haiku 4.5
Full security profile
Google Gemini 2.0 Flash

Frequently asked questions

Is Anthropic Claude Haiku 4.5 or Google Gemini 2.0 Flash 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 Gemini 2.0 Flash scores 33.6% 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 Gemini 2.0 Flash?

Claude Haiku 4.5 has a 5.2% ASR and Gemini 2.0 Flash has a 33.6% 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 Gemini 2.0 Flash 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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