Model reference · open weights
NVIDIA-Nemotron-3-Ultra is an open-weight language model from nvidia, listed in the AxForge catalogue. AxForge can bring it up on EU-owned hardware for you on request — with the licence handled where one is required.
About
NVIDIA-Nemotron-3-Ultra-550B-A55B-NVFP4 Model Summary Quick Start For more details on how to deploy and use the model - see the Quick Start Guide below! Model Overview Model Developer: NVIDIA Corporation Model Dates: December 2025 - April 2026 Data Freshness: The post-training data has a cutoff date of May 2026. The pre-training data has a cutoff date of September 2025. What is Nemotron? NVIDIA Nemotron™ is a family of open models with open weights, training data, and recipes, delivering leading efficiency and accuracy for building specialized AI agents. Description Nemotron-3-Ultra-550B-A55B-NVFP4 is a frontier-scale large language model (LLM) trained by NVIDIA, designed to deliver strong agentic, reasoning, and conversational capabilities. It is optimized for the most demanding workloads, including complex multi-step agents, long-context analysis, and high-accuracy reasoning over code, math, and science. Like other models in the family, it responds to user queries and tasks by first generating a reasoning trace and then concluding with a final response. The model's reasoning capabilities can be configured through a flag in the chat template. The model employs a hybrid Latent Mixture-of-Experts (LatentMoE) architecture, utilizing interleaved Mamba-2 and MoE layers, along with select Attention layers. Like the Super model, the Ultra model incorporates Multi-Token Prediction (MTP) layers for faster text generation and improved quality, and it is trained using an NVFP4 pre-training recipe to maximize compute efficiency. The model has 55B active parameters and 550B parameters in total. The supported languages include: English, French, Spanish, Italian, German, Japanese, Korean, Hindi, Brazilian Portuguese, and Chinese. This model is ready for commercial and non-commercial use. License/Terms of Use Governing Download Terms: Use of this model is governed by the OpenMDW-1.1 model license. Benchmarks All evaluation results were collected via Nemo Evaluator SDK. We used three main evaluation harnesses: Nemo Gym, Nemo Skills, and Harbor with extended sandboxing support via AWS ECS on Nemo Evaluator. In addition, the evaluations also used dedicated open-source packaged co
Summarised from the published model card. Read the full card on the HuggingFace links below.
Specifications
| Maker | nvidia |
|---|---|
| Type | Language models |
| Parameters (lead) | 302.8B |
| Variants | 2 |
| Runs with | transformers |
| Released | 2026-06-03 |
| Popularity | 404k downloads / month |
| Likes | 335 |
| Licence | Commercial licence needed |
How it works
Variants
Open weights ship in several sizes and precisions. One page, all the variants — pick the one that fits your GPU. VRAM figures are estimates from model size.
Using it via the API
Once AxForge deploys nvidia-nemotron-3-ultra for you, it answers on the OpenAI-compatible API — the same base URL and keys as every other model. (nvidia-nemotron-3-ultra below is illustrative; you get the exact model name on deployment.)
$ curl -sS https://api.axforge.ai/v1/chat/completions \
-H "Authorization: Bearer $AXFORGE_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model":"nvidia-nemotron-3-ultra","messages":[{"role":"user","content":"Hello"}]}'
Details
Languages
Trained / evaluated on
Tags
Licence
The weights are open but its licence needs a commercial agreement for business use. AxForge can arrange that licence and host the model for you — you pay AxForge, we settle with the model’s maker. Ask us for a quote. Read the licence ↗
Sources