OpenAI GPT OSS 120B vs xAI Grok-4 Fast Non-Reasoning
Detailed comparison for LLMs
On Guardion's LLM vulnerability Benchmark, OpenAI GPT OSS 120B is the more secure of the two: GPT OSS 120B scores 15.0% and Grok-4 Fast Non-Reasoning scores 33.0% 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 120B is the overall winner in this comparison!
Attack Success Rate (lower is safer)
ASR for OpenAI GPT OSS 120B vs xAI Grok-4 Fast Non-Reasoning. 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 120B has a lower Overall (ASR).
Security Profile
Outward is better on every axis.
Frequently asked questions
Is OpenAI GPT OSS 120B or xAI Grok-4 Fast Non-Reasoning more secure?
On Guardion's LLM vulnerability Benchmark, OpenAI GPT OSS 120B is the more secure of the two: GPT OSS 120B scores 15.0% and Grok-4 Fast Non-Reasoning scores 33.0% 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 120B vs Grok-4 Fast Non-Reasoning?
GPT OSS 120B has a 15.0% ASR and Grok-4 Fast Non-Reasoning has a 33.0% ASR — the share of adversarial prompts that succeed across zero-shot, TAP, and Crescendo attacks. Lower is safer.
How were GPT OSS 120B and Grok-4 Fast Non-Reasoning 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.