OpenAI GPT OSS 20B vs Google Gemini 2.0 Flash Thinking
Detailed comparison for LLMs
On Guardion's LLM vulnerability Benchmark, OpenAI GPT OSS 20B is the more secure of the two: GPT OSS 20B scores 20.0% and Gemini 2.0 Flash Thinking scores 21.5% 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
GPT OSS 20B is the overall winner in this comparison!
Attack Success Rate (lower is safer)
ASR for OpenAI GPT OSS 20B vs Google Gemini 2.0 Flash Thinking. 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
- OpenAI GPT OSS 20B has a lower Overall (ASR).
Security Profile
Outward is better on every axis.
Frequently asked questions
Is OpenAI GPT OSS 20B or Google Gemini 2.0 Flash Thinking more secure?
On Guardion's LLM vulnerability Benchmark, OpenAI GPT OSS 20B is the more secure of the two: GPT OSS 20B scores 20.0% and Gemini 2.0 Flash Thinking scores 21.5% 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 OSS 20B vs Gemini 2.0 Flash Thinking?
GPT OSS 20B has a 20.0% ASR and Gemini 2.0 Flash Thinking has a 21.5% ASR — the share of adversarial prompts that succeed across zero-shot, TAP, and Crescendo attacks. Lower is safer.
How were GPT OSS 20B and Gemini 2.0 Flash Thinking 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.