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Nemotron 3 Ultra

NVIDIAReleased Jun 4, 2026

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...

Try in playground
Context window
1M tokens
Max output
16K tokens
Input
text
Output
text
Tokenizer
Other
Released
Jun 4, 2026
Reasoning
optional

Pricing

Per 1M tokens. The provider price and our flat 3% fee are separate columns — what you pay is their sum.

Per 1M tokensProvider+ 3% feeYou pay
Input$0.500$0.015$0.515
Output$2.20$0.066$2.27
Cache read$0.100$0.0030$0.103

Benchmarks

Artificial Analysis

Intelligence index
37.8
Coding index
49.3
Agentic index
27.4

Design Arena

CategoryEloWin rateRank
3Dmodels121343.6%#40
ASCII artmodels109335.8%#44
Codemodels117437%#60
Data vizmodels116738.7%#63
Game devmodels119539.3%#53
SVGmodels114038.6%#45
UI componentsmodels118038.7%#54
Websitesmodels114032.6%#76

Head-to-head preference voting. How we filter and rank

Supported parameters

  • frequency_penalty
  • include_reasoning
  • logit_bias
  • max_tokens
  • min_p
  • presence_penalty
  • reasoning
  • repetition_penalty
  • response_format
  • seed
  • stop
  • structured_outputs
  • temperature
  • tool_choice
  • tools
  • top_k
  • top_p

Call it

OpenAI-compatible: point your SDK at api.openkey.ai/v1 and use model nvidia/nemotron-3-ultra-550b-a55b.

Code sample language
curl https://api.openkey.ai/v1/chat/completions \
  -H "Authorization: Bearer $OPENKEY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "nvidia/nemotron-3-ultra-550b-a55b",
    "messages": [{"role": "user", "content": "Hello"}]
  }'
import os
from openai import OpenAI

client = OpenAI(
    base_url="https://api.openkey.ai/v1",
    api_key=os.environ["OPENKEY_API_KEY"],
)

completion = client.chat.completions.create(
    model="nvidia/nemotron-3-ultra-550b-a55b",
    messages=[{"role": "user", "content": "Hello"}],
)
print(completion.choices[0].message.content)
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.openkey.ai/v1",
  apiKey: process.env.OPENKEY_API_KEY,
});

const completion = await client.chat.completions.create({
  model: "nvidia/nemotron-3-ultra-550b-a55b",
  messages: [{ role: "user", content: "Hello" }],
});
console.log(completion.choices[0].message.content);

Questions

How much does Nemotron 3 Ultra cost via API?
Through OpenKey, Nemotron 3 Ultra costs $0.515 per 1M input tokens and $2.27 per 1M output tokens. That is the provider price ($0.500 / $2.20) plus a flat 3% fee — nothing else.
What is Nemotron 3 Ultra's context window?
Nemotron 3 Ultra accepts up to 1M tokens of context and returns up to 16K tokens per request.
Is Nemotron 3 Ultra OpenAI-compatible?
Yes. Send requests to OpenKey's /v1/chat/completions endpoint with model "nvidia/nemotron-3-ultra-550b-a55b" using any OpenAI SDK — only the base URL and API key change.
What inputs does Nemotron 3 Ultra support?
Nemotron 3 Ultra accepts text input and produces text output.

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