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NVIDIA: Nemotron 3 Ultra (batch)

nvidia/nemotron-3-ultra-550b-a55b:batch · NVIDIATokenizer lineage measured

Tokenizer lineage (measured): Mistral
Evidence confidence: High
Declared tokenizer tag: Other
Entered catalogue: 4 June 2026
Last tested: Not yet measured
Measurement: Variant: inherits its base model’s measurement

Evidence

✓ inherited from nvidia/nemotron-3-ultra-550b-a55b: a serving variant shares its base model's tokenizer

Compare with NVIDIA: Nemotron 3 Ultra

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Withdrawn from the catalogue

First absent from the snapshot of 3 September 2026

NVIDIA: Nemotron 3 Ultra (batch) no longer appears in the OpenRouter catalogue. The record stays here because the measurements below were real when they were taken and this address has been published. A model leaving is the kind of change this product exists to notice, so it is kept rather than deleted.

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.

Identity statement

NVIDIA: Nemotron 3 Ultra (batch) is NVIDIA's model. Its measured tokenizer sits with the Mistral group, which is evidence that it builds on the Mistral tokenizer. Tokenizer reuse is normal engineering, open vocabularies travel between labs, and this says nothing against NVIDIA's authorship of the model itself.

Evidence stack

Signals of different kinds, weighed together

Signal	Result	Reference
Tokenizer signature	Not measured	–
API surface	No other entry shares this exact contract	api_d0c2ec50
Context and output	512,288 context · – max output	declared
Reasoning contract	Optional · efforts high, medium · default high	declared
Serving providers observed	None 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: $0.60 / M tokens
Completion price: $3.60 / M tokens

Supported parameters

frequency_penaltyinclude_reasoninglogit_biasmax_tokensmin_ppresence_penaltyreasoningreasoning_effortrepetition_penaltyresponse_formatstopstructured_outputstemperaturetool_choicetoolstop_ktop_p

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

Catalogue entry Weights 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 (batch): the URL is stable, measurements are dated, and revisions append to the history above. Method: tokenizer fingerprinting, v1, 50 strings.