Model Comparison
Llama 3.1 405B Instruct vs Llama 3.1 Nemotron Ultra 253B v1Which is better in 2026?
Llama 3.1 Nemotron Ultra 253B v1 significantly outperforms across most benchmarks.
Verdict: Llama 3.1 405B Instruct vs Llama 3.1 Nemotron Ultra 253B v1 — which is better?
Llama 3.1 405B Instruct (by Meta) and Llama 3.1 Nemotron Ultra 253B v1 (by NVIDIA) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
Llama 3.1 405B Instruct outperforms in 0 benchmarks, while Llama 3.1 Nemotron Ultra 253B v1 is better at 2 benchmarks (GPQA, IFEval). Llama 3.1 Nemotron Ultra 253B v1 significantly outperforms across most benchmarks.
Choose Llama 3.1 405B Instruct if…
- you want predictable pricing at $0.89/M input and $0.89/M output
Choose Llama 3.1 Nemotron Ultra 253B v1 if…
- you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
- you want the most recent training data — it shipped Apr 2025
Performance Benchmarks
Comparative analysis across standard metrics
Llama 3.1 405B Instruct outperforms in 0 benchmarks, while Llama 3.1 Nemotron Ultra 253B v1 is better at 2 benchmarks (GPQA, IFEval).
Llama 3.1 Nemotron Ultra 253B v1 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Model Size
Parameter count comparison
Llama 3.1 405B Instruct has 152.0B more parameters than Llama 3.1 Nemotron Ultra 253B v1, making it 60.1% larger.
Context Window
Maximum input and output token capacity
Only Llama 3.1 405B Instruct specifies input context (128,000 tokens). Only Llama 3.1 405B Instruct specifies output context (128,000 tokens).
License
Usage and distribution terms
Both models are licensed under Llama 3.1 Community License.
Both models share the same licensing terms, providing consistent usage rights.
Llama 3.1 Community License
Open weights
Llama 3.1 Community License
Open weights
Release Timeline
When each model was launched
Llama 3.1 405B Instruct was released on 2024-07-23, while Llama 3.1 Nemotron Ultra 253B v1 was released on 2025-04-07.
Llama 3.1 Nemotron Ultra 253B v1 is 9 months newer than Llama 3.1 405B Instruct.
Jul 23, 2024
2.0 years ago
Apr 7, 2025
1.3 years ago
8mo newerKnowledge Cutoff
When training data ends
Llama 3.1 Nemotron Ultra 253B v1 has a documented knowledge cutoff of 2023-12-01, while Llama 3.1 405B Instruct's cutoff date is not specified.
We can confirm Llama 3.1 Nemotron Ultra 253B v1's training data extends to 2023-12-01, but cannot make a direct comparison without Llama 3.1 405B Instruct's cutoff date.
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Dec 2023
Outputs Comparison
Key Takeaways
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Llama 3.1 405B Instruct and Llama 3.1 Nemotron Ultra 253B v1 side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Llama 3.1 405B Instruct vs Llama 3.1 Nemotron Ultra 253B v1.