Nemotron 3 Ultra (free)

What is Nemotron 3 Ultra (free)?

Nemotron 3 Ultra is NVIDIA’s model for reasoning and agent orchestration. OpenRouter offers a free endpoint for text input and output, useful for an initial experiment with public or synthetic material. NVIDIA explicitly warns against confidential and personal inputs on that endpoint because usage is logged for security and product improvement.

A useful place for non-sensitive experiments

NVIDIA describes Nemotron 3 Ultra as a reasoning and orchestration model for multi-step work. Use public documentation or invented records to explore whether a model can propose an ordered plan, select an appropriate tool and explain what remains unresolved.

For example, create a fictional support ticket and a small public troubleshooting guide. Ask for a next step grounded in the guide, then deliberately remove a required fact. A useful result should ask for that fact rather than make up a device state or promise a successful fix.

Suggested workflow: test a support decision

Write five synthetic tickets with expected outcomes, including one ambiguous request and one case that needs escalation. Provide the same short guide with each ticket. First ask for a proposed decision without allowing actions.

Check whether the answer cites the relevant passage and respects the escalation rule. If you later add tools, start with a harmless mock tool that only returns test data. Record incorrect decisions and revise the instructions before connecting a real system.

What free access actually means

Use the exact OpenRouter identifier nvidia/nemotron-3-ultra-550b-a55b:free. The model-token price is zero, but OpenRouter caps free models at 20 requests per minute and 50 per day (1,000 per day once your account has bought at least $10 of credits), and failed attempts count toward the cap. NVIDIA’s trial terms allow only internal testing and evaluation, not production use. When we checked on October 17, 2026, OpenRouter showed low availability for this endpoint, so check the model page before relying on it.

The endpoint notice says NVIDIA logs usage for security and to improve its products and services. Follow its restriction on confidential and personal data. If your work needs private material, evaluate an appropriate paid or separately deployed route and its terms instead of assuming all Nemotron access has the same policy.

Evaluate the result, not the zero price

A free experiment can show whether your task is well specified, but errors still cost review time. Compare the percentage of usable decisions and the work needed to correct them. For a production choice, include access reliability, data requirements and your own evaluation results.