NVIDIA: Llama 3.1 Nemotron Ultra 253B v1
Llama-3.1-Nemotron-Ultra-253B-v1 is a large language model (LLM) optimized for advanced reasoning, human-interactive chat, retrieval-augmented generation (RAG), and tool-calling tasks. Derived from Meta’s Llama-3.1-405B-Instruct, it has been significantly customized using Neural Architecture Search (NAS), resulting in enhanced efficiency, reduced memory usage, and improved inference latency. The model supports a context length of up to 128K tokens and can operate efficiently on an 8x NVIDIA H100 node. Note: you must include `detailed thinking on` in the system prompt to enable reasoning. Please see [Usage Recommendations](https://huggingface.co/nvidia/Llama-3_1-Nemotron-Ultra-253B-v1#quick-start-and-usage-recommendations) for more.
Pricing per 1M Tokens
| Input (Prompt) | $0.60 |
| Output (Completion) | $1.80 |
| Cache Read | Free |
| Cache Write | Free |
| Image | N/A |
Specifications
| Context Length | 131K |
| Max Output Tokens | N/A |
| Input Modalities | Text |
| Output Modalities | Text |
| Tokenizer | Llama3 |
| Instruct Type | N/A |
| Top Provider Context | 131K |
| Top Provider Max Output | N/A |
| Moderated | No |
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Last updated: March 23, 2026
First tracked: March 23, 2026