by Nvidia
NVIDIA Nemotron 3 Ultra is an open frontier-reasoning and orchestration model featuring an extensive 1,000,000-token context length. Built on a hybrid Transformer-Mamba mixture-of-experts (MoE) architecture, it operates with 55B active parameters out of a total of 550B parameters. This advanced structure is designed to support sophisticated reasoning and complex task orchestration.
| Context window | 1,000,000 tokens |
| Modalities | text |
| Features | reasoning, tool_calling, long_context |
| Endpoints | chat_completions |
Use nemotron-3-ultra-550b-a55b-free via the AIHubMix unified API — one interface for every major LLM.