Llama 3.1 Nemotron Ultra 253B
Summary
Llama 3.1 Nemotron Ultra 253B is an open-weight language model from NVIDIA, released on 7 Apr 2025. It accepts text and generates text, with a 128K-token context window and up to 16K output tokens per response.
Flagship Nemotron model for high-throughput reasoning and complex agents
Last verified 4 Oct 2026. Every figure on this page links to its source.
Specifications
| Developer | NVIDIA |
|---|---|
| Release date | 7 Apr 2025 [models.dev] |
| Status | Generally available [models.dev] |
| Weights | Open weights [models.dev] |
| Context window | 128K (128,000 tokens) [models.dev] |
| Max output | 16K tokens [models.dev] |
| Input | Text [models.dev] |
| Output | Text [models.dev] |
| Reasoning mode | Yes [models.dev] |
| Tool calling | Yes [models.dev] |
Llama 3.1 Nemotron Ultra 253B API pricing by provider
USD per million tokens. Sorted by input price.
| Provider | Input | Output | Cached input | Context | Source |
|---|---|---|---|---|---|
| NVIDIA NIM nvidia/llama-3.1-nemotron-ultra-253b-v1 | Free | Free | – | 128K | models.dev, 4 Oct 2026 |
Frequently asked questions
What is the context window of Llama 3.1 Nemotron Ultra 253B?
Llama 3.1 Nemotron Ultra 253B has a context window of 128,000 tokens (128K) and can generate up to 16,384 tokens in a single response, according to models.dev.
Is Llama 3.1 Nemotron Ultra 253B open source?
Llama 3.1 Nemotron Ultra 253B is an open-weight model. Check the license terms before commercial use.
When was Llama 3.1 Nemotron Ultra 253B released?
NVIDIA released Llama 3.1 Nemotron Ultra 253B on 7 Apr 2025, according to models.dev.
Change history
No changes detected since we started tracking this model. We re-check every source daily.