Nemotron 3 Ultra (free) vs DeepSeek V4 Flash 0731

NVIDIA Nemotron 3 Ultra is an open frontier-reasoning and orchestration model from NVIDIA, with 55B active parameters out of 550B total (MoE). Built on a hybrid Transformer-Mamba mixture-of-experts architecture, it supports text input and output with a context window of up to 1M tokens. It is suited for long-running agentic workflows, including agent orchestration, coding agents, deep research, and complex enterprise tasks. It is particularly strong at multi-step reasoning and planning, with high-throughput inference designed for high-volume agent pipelines. It is part of the NVIDIA Nemotron family of open models for agentic AI.

DeepSeek V4 Flash 0731 is the official release of DeepSeek V4 Flash, superseding the preview version, with substantially enhanced agentic capabilities. It is a sparse mixture-of-experts model with 13B active parameters out of 284B total, and this re-post-trained revision is suited for coding, reasoning, and agent workflows. The model natively supports a 1M-token context window and flexible reasoning effort: low for simple tasks, high for daily agent workflows, and max for complex ones.