NVIDIA: Nemotron 3 Ultra (free)

nvidia/nemotron-3-ultra-550b-a55b:free · NVIDIAUnmeasurable
Declared family
Unknown
Evidence confidence
Unknown
Declared tokenizer tag
Other
Entered catalogue
4 June 2026
Last tested
Not yet measured
Measurement
Variant: inherits its base model’s measurement

This entry is a serving variant of NVIDIA: Nemotron 3 Ultra. A variant shares its base model's tokenizer by construction, so the measurement lives on the base record and this page inherits it.

Evidence stack

Signals of different kinds, weighed together
SignalResultReference
Tokenizer signatureNot measured
API surfaceNo other entry shares this exact contractapi_5824e6f4
Context and output1,000,000 context · 65,536 max outputdeclared
Reasoning contractOptional · efforts high, medium · default highdeclared
Serving providers observedNone recorded yet

Declared record

What the catalogue claims about this model

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...

Modalities
text->text
Declared tokenizer
Other
Prompt price
$0 / M tokens
Completion price
$0 / M tokens

Supported parameters

include_reasoningmax_tokensreasoningreasoning_effortseedtemperaturetool_choicetoolstop_p

defaults: {"temperature":1,"top_p":0.95,"top_k":null,"frequency_penalty":null,"presence_penalty":null,"repetition_penalty":null}

Catalogue entryWeights on Hugging Face

History

Every observation, kept as taken
  • 4 June 2026Enters the OpenRouter catalogue with no declared family.

Cite this page as the evidence record for NVIDIA: Nemotron 3 Ultra (free): the URL is stable, measurements are dated, and revisions append to the history above. Method: tokenizer fingerprinting, v1, 50 strings. The raw data behind every figure is on the data page.