Meta Llama 4 Scout vs NVIDIA Llama 3.1 Nemotron Ultra 253B v1

Detailed comparison for LLMs

MetaNVIDIA

On Guardion's LLM vulnerability Benchmark, Meta Llama 4 Scout is the more secure of the two: Llama 4 Scout scores 30.0% and Llama 3.1 Nemotron Ultra 253B v1 scores 40.0% 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

Llama 4 Scout is the overall winner in this comparison!

Attack Success Rate (lower is safer)

ASR for Meta Llama 4 Scout vs NVIDIA Llama 3.1 Nemotron Ultra 253B v1. Green marks the safer model on each metric. Only the overall score is available for estimated models.

Overall (ASR)

Llama 4 Scout
30.0%
Llama 3.1 Nemotron Ultra 253B v1
40.0%

TAP Attack Method (ASR)

Llama 4 Scout
63.5%
Llama 3.1 Nemotron Ultra 253B v1
100.0%

Crescendo Attack Method (ASR)

Llama 4 Scout
20.3%
Llama 3.1 Nemotron Ultra 253B v1
100.0%

Zero-Shot (ASR)

Llama 4 Scout
6.1%
Llama 3.1 Nemotron Ultra 253B v1
100.0%

Key Highlights

  • Meta Llama 4 Scout has a lower Overall (ASR).
  • Meta Llama 4 Scout has a lower TAP Attack Method (ASR).
  • Meta Llama 4 Scout has a lower Crescendo Attack Method (ASR).
  • Meta Llama 4 Scout has a lower Zero-Shot (ASR).

Security Profile

Outward is better on every axis.

OverallTAPCrescendoZero-Shot
Llama 4 Scout
Llama 3.1 Nemotron Ultra 253B v1
Full security profile
Meta Llama 4 Scout
Full security profile
NVIDIA Llama 3.1 Nemotron Ultra 253B v1

Frequently asked questions

Is Meta Llama 4 Scout or NVIDIA Llama 3.1 Nemotron Ultra 253B v1 more secure?

On Guardion's LLM vulnerability Benchmark, Meta Llama 4 Scout is the more secure of the two: Llama 4 Scout scores 30.0% and Llama 3.1 Nemotron Ultra 253B v1 scores 40.0% 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 Llama 4 Scout vs Llama 3.1 Nemotron Ultra 253B v1?

Llama 4 Scout has a 30.0% ASR and Llama 3.1 Nemotron Ultra 253B v1 has a 40.0% ASR — the share of adversarial prompts that succeed across zero-shot, TAP, and Crescendo attacks. Lower is safer.

How were Llama 4 Scout and Llama 3.1 Nemotron Ultra 253B v1 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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