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NVIDIA · FIELD VERIFIED
NVIDIA Nemotron 3.5 Transcribe 30B-A4B
Primary sources last checked on 30 Oct 2026. Verification freshness is tracked separately from factual change, and unknown values remain explicit rather than inferred.
NotableNew October 28 original NVIDIA BF16 speech-processing release: downloadable checkpoint, publisher-reported 40-language offline ASR, translation and speaker-attributed transcripts, first-party technical evidence and OpenMDW-1.1. Reported WER is not an independent OMW performance measurement.Curation method →
Open Model Weights records NVIDIA Nemotron 3.5 Transcribe 30B-A4B as a 34B total / 4.3B active (publisher-declared)-parameter audio and text instructions → text and word timestamps open-weight model in the Nemotron 3.5 Transcribe family, with NVIDIA listed as the developer. The checked source repository provides 1 recognized weight artifacts, format evidence for Safetensors and a verified context window of 262,144 tokens. Values that are not evidenced in the checked sources remain explicitly undisclosed or unknown.
The repository declares NVIDIA OpenMDW License Agreement v1.1. NVIDIA permits commercial and noncommercial model use subject to OpenMDW-1.1, redistribution notices and applicable component terms.. Open Model Weights reports the checked license evidence and classification; this is not legal advice.
The checked sources declare nvidia/NVIDIA-Nemotron-3.5-Lightning-30B-A3B-BF16 as lineage evidence. Training recipe status: training-described-in-model-card; data disclosure status: dataset-metadata-declared.
NVIDIA Nemotron 3.5 Transcribe 30B-A4B is an officially released open-weight offline speech and audio model combining a speech encoder with a sparse language backbone. NVIDIA reports 34 billion total parameters including audio components, approximately 4.3 billion active, support for 40 languages and recordings up to one hour. The source-verified repository declares OpenMDW License Agreement v1.1. Open Model Weights classifies the original BF16 checkpoint as Notable for speech transcription, translation and speaker-attributed word timestamps; publisher WER or throughput reports are not independent OMW tests.
Original BF16 checkpointNVIDIA official downloadable weight file and model card; revision-linked in the canonical registrySource ↗
ArchitecturePublisher: approximately 34B total including audio encoder, 4.3B activeSource ↗
Language and duration scope40 languages and recordings of up to one hour; publisher-declared offline processingSource ↗
Reported WER4.71% English and 4.62% multilingual publisher-reported mean WER; no OMW independent replicationSource ↗
Licensed model useOpenMDW License Agreement 1.1 with conditions; commercial and noncommercial permissions are not unrestrictedSource ↗
Original publicationOctober 28, 2026, with named checkpoint variants and source-linked technical documentationSource ↗
No OMW runtime measurementNVIDIA WER, throughput and diarization results are manufacturer-reported; OMW independently checked only public-source fieldsSource ↗
WHY IT MATTERS
The release is a distinct, reproducible speech-specialist checkpoint rather than another generic chat model or a runtime-only feature announcement.
Publisher-described tasks include verbatim and normalized transcripts, prompted terms, translation, language identification, speaker diarization and timestamp-rich output.
An official downloadable checkpoint, dedicated technical explanation and explicit conditional OpenMDW-1.1 grant make the release useful for informed offline speech deployments.
MODEL-SELECTION VIEW
Strong fit when…
Batch audio transcription and speaker-attributed output from recorded meetings, research interviews or documentary audio.
Engineering teams that want an original downloadable NVIDIA checkpoint and explicit license/evidence trail instead of unverified model-card performance claims.
Important considerations
Offline file-level transcription is not a proof of low-latency real-time streaming; NVIDIA distinguishes the public model from optimized proprietary NIM additions.
Publisher WER results are not OMW measurements. Evaluation requires task, language, audio condition, speaker and context matching.
BF16, FP8, NVFP4, GGUF and companion speculative drafters are distinct artifacts with potentially different memory, throughput and integration requirements.
Actual recordings can contain personally identifiable or confidential data. Assess capture consent, retention policy, privacy and model output verification.
What the open speech checkpoint can do
NVIDIA describes speech instruction-following tasks including verbatim ASR, normalized transcripts, language identification, cross-language translation, audio question answering and diarized transcripts with word timestamps. A 40-language coverage claim needs real-language and noise-conditioned evaluation, not a generic guarantee of equal recognition quality.
The released BF16 model's repository is the source for weights and configuration. Additional optimized variants and speculative drafts should be identified by separate checkpoint IDs instead of being falsely presented as new independent model architectures.
Parameters, audio components and practical serving
The system contains an audio front end and a sparse language component. NVIDIA's 34B total and approximately 4.3B active counts are publisher architecture claims, not a measurement that the complete model fits in 4.3B-equivalent weight memory.
The NVIDIA research description says offline processing covers up to one-hour recordings. Operational throughput and peak memory depend on encoder preprocessing, windowing, speaker attribution, batching, runtime optimization and device capacity.
What NVIDIA's reported performance does not prove
NVIDIA reports mean WER of 4.71% on an English Open ASR collection and 4.62% on the multilingual selection, with separate analyses of overlapping speakers and named entities. The numbers are useful provenance, but remain publisher-supplied.
Some high-throughput NIM-serving results rely on performance optimizations not yet part of the public release. Open Model Weights has not run the checkpoint, replicated WER, validated speaker diarization or measured streaming behavior.
Why Notable rather than Leading
Notable highlights specialist relevance with downloadable official weights and source-described evaluation scope. This checkpoint addresses speech-to-text quality, not general-purpose language intelligence ranking.
Without a reviewed independent, checkpoint-equivalent evaluation against peer offline speech models, Leading would overstate the evidence. The original license and file manifest remain more important than a promotional rank.
Variant selection and preprocessing fidelity
The published BF16 source checkpoint is the reference for this entry; FP8, NVFP4, GGUF and draft components are distinct distributions, each with an exact model identifier and their own runtime prerequisites. The audio encoder, speaker-information network and text processor affect the end-to-end data path.
A meaningful deployment audit must record resampling, channel count, signal duration, language prompts, speaker hints, chunk treatment and timestamp alignment along with the model revision. Small pipeline differences can substantially change word-error and diarization results without changing the underlying source model.
Multilingual evaluation and recorded-data safeguards
Forty-language support is a declared model scope, not a promise of uniform accuracy across accents, noisy rooms, dialects or specialist vocabularies. Build separate language- and speaker-stratified test sets, retain reference transcriptions, calculate error metrics against the intended task and review time-aligned outputs manually.
Speech recordings often contain third-party personal data. Consent, retention, geographic processing, access control and human confirmation of quoted words matter as much as model choice. Offline processing can help manage data locality, but the way operators actually capture, store and route audio still determines privacy risk.
IMPLEMENTATION & EVALUATION
How to evaluate NVIDIA Nemotron 3.5 Transcribe 30B-A4B before deployment
A reproducible offline ASR evaluation plan; these steps are not claims that Open Model Weights ran the model.
STEP 01
Pin the BF16 checkpoint and audio path
Audio systems may require separate encoder, tokenizer and task templates.
REPRODUCIBLE ACCEPTANCE TEST
Record exact repository SHA, weight manifest, preprocessing parameters, code revision, language settings and output schema.
WHAT CAN GO WRONG
Counting third-party quantized weights as the original or omitting audio preprocessing dependencies.
STEP 02
Build multilingual and speaker-aware test clips
Recognition errors vary with accent, language, noise, overlap and vocabulary.
REPRODUCIBLE ACCEPTANCE TEST
Score task-specific WER/CER, timing accuracy and diarization per test subset, separately from translated output quality.
WHAT CAN GO WRONG
Applying a single English WER to every speaker and language or treating time-aligned word text as guaranteed.
STEP 03
Inspect license, privacy and throughput
Real-world recorded speech introduces personal-data and serving constraints.
REPRODUCIBLE ACCEPTANCE TEST
Verify OpenMDW-1.1 notices, consent/retention requirements, actual peak memory, CPU/GPU use and end-to-end latency.
WHAT CAN GO WRONG
Mistaking a publisher-optimized NIM benchmark for the public weights or streaming inference performance.
STEP 04
Report publisher and owner benchmarks separately
Serving-optimized benchmark results may require components not released with the checkpoint.
REPRODUCIBLE ACCEPTANCE TEST
Separate attributed NVIDIA WER and NIM claims from any measured local runs, with full hardware and audio-test conditions documented.
WHAT CAN GO WRONG
Reporting publisher-only metrics as independently observed or assuming non-upstreamed speedups exist in the public weights.
Questions people ask about NVIDIA Nemotron 3.5 Transcribe 30B-A4B.
Is Nemotron 3.5 Transcribe a general chat model?
No. This original checkpoint is built for speech and audio-conditioned instruction processing. Its Notable selection is specialist relevance, not a general intelligence ranking.
Does Nemotron 3.5 Transcribe stream audio in real time?
NVIDIA describes an offline system for recordings up to one hour, not a validated real-time streaming ASR API. Local production streaming capability has not been verified by Open Model Weights.
Are the published word error rates independently verified?
No. WER claims are attributed to NVIDIA; Open Model Weights has not run a matched benchmark.
Can the NVIDIA weights be used commercially?
NVIDIA's OpenMDW License Agreement v1.1 includes conditional commercial and noncommercial permission. Read the current license and notices for the exact model and intended use.
Are 34B total and 4.3B active parameters interchangeable for storage planning?
No. The 34B count includes the audio-related components, while active parameters describe a sparse model's computation on a token. Neither figure alone determines downloaded checkpoint bytes, GPU memory or serving throughput.
Is NVIDIA's model automatically the best open ASR checkpoint?
No. Our Notable designation reflects a distinct, verifiable specialist release. Comparative leadership would require an independent speech evaluation of matching public checkpoints, tasks and datasets, which Open Model Weights has not performed.
03 · PRACTICAL TECHNICAL PROFILE
Deployment, licensing and reproducible evidence.
Inspect weight-memory estimates, model lineage and runtime evidence separately from promotional or untested performance claims.
DEPLOYMENT PROFILE
Weight memory, without pretending it is a deployment guarantee.
These bars visualize weight-only decimal-GB estimates. They exclude KV cache, activations, runtime overhead, optimizer state and sharding.
WEIGHT-ONLY MEMORY
BF16 / FP16~68.0 GB
FP8 / INT8~34.0 GB
INT4~17.0 GB
FIELD EVIDENCE MAP
WeightsVerified
LicenseVerified
Commercial useAllowed with conditions
ContextVerified
FormatsVerified
LineageDeclared
Training recipeTraining described in model card
Training dataDataset metadata declared
RuntimeSource-derived · not runtime-tested
LICENSE & USE
NVIDIA OpenMDW License Agreement v1.1
NVIDIA permits commercial and noncommercial model use subject to OpenMDW-1.1, redistribution notices and applicable component terms.
NVIDIA Nemotron 3.5 Transcribe 30B-A4B: technical evidence at a glance
Three evidence-linked visual summaries: parameter scale, illustrative precision memory and verifiable provenance. No performance ranking is implied.
01 / PARAMETER SCALE
Total versus active parameters
Total parameters34B
Active parameters · publisher4.3B
Repository-derived or publisher-described parameter count
Total and active parameters describe different published quantities, not inference speed or runtime memory.
02 / MEMORY ESTIMATE
Weight-only precision footprint
BF16 / FP1668 GB
FP8 / INT834 GB
INT417 GB
Hypothetical weight-only decimal GB, not measured peak VRAM or guaranteed support for each format. KV cache, activations, runtime and sharding are excluded.
Repository SHA c17667641642…; a source check is not an inference benchmark or legal clearance. See the per-model evidence JSON for the exact source record.
A verification check does not pretend the model changed. Open Model Weights updates the verification date after a real primary-source check, while factual-update dates move only when retained source evidence changes.
No active conflict · 1 comparison signalSource values differ in scope, granularity or claim strength; OMW does not overstate those differences as contradictions.
Comparison signals are not conflicts.1 current signal keeps scope/granularity differences visible without asserting contradiction.
COMPARISON SIGNALtotal parameters billionsscope or granularity difference
Weight-only decimal-GB estimate from total parameter count; excludes KV cache, activations, runtime overhead, optimizer state and sharding.
04 · FORMATS
Formats & precision evidence
Safetensors
BF16: not observedFP16: not observedFP8: not observedINT8: not observedINT4: not observedGGUF: not observed
“Not observed” means no matching repository artifact/name/dtype signal was found; it does not prove no third-party conversion exists.
05 · LINEAGE
Base model & family
FamilyNemotron 3.5 Transcribe
VariantBF16
Declared base modelnvidia/NVIDIA-Nemotron-3.5-Lightning-30B-A3B-BF16
Relationbase_model
06 · TRAINING ASSETS
Recipe & data disclosure
Training recipetraining-described-in-model-card
Data disclosuredataset-metadata-declared
EvaluationsNot classified by automated verifier
Intermediate checkpointsNot classified by automated verifier
07 · RUNTIME SUPPORT
Declared, mentioned and externally evidenced runtimes
Declared librarynemo
Declared/taggednemo
Mentioned in model cardNeMo, SGLang, Transformers, vLLM
Artifact signalsNone
External primary runtime evidenceNone
Tested by Open Model WeightsNo — source-derived support only
Open Model Weights separates model-repository evidence from external runtime-release evidence. An external support statement does not change the official model repository's weight formats and does not imply an Open Model Weights inference benchmark.
Official Hugging Face repository SHA unchanged; prior field evidence retained.
Field-by-field verification
Checked Hugging Face API metadata, exact repository file list, model card and config when accessible.
licenseverified
commercial useclassified
contextverified
weight filesverified
formatsverified
base modeldeclared
training recipetraining-described-in-model-card
data disclosuredataset-metadata-declared
runtime supportsource-derived-not-runtime-tested
MODELS FOR AI AGENTS · ROLE EVIDENCE
Where this model fits in an agent system
Specialized model. A supporting component. This checkpoint does not, by category alone, serve as the planning and tool-execution controller.
The curated notable tier is not an agent-readiness rating. Model-specific tool-call success, long-horizon task accuracy and compatible runtime configurations are not independently established here.
Source-linked license: NVIDIA OpenMDW License Agreement v1.1 (allowed-with-conditions commercial-use classification; see original terms).
Context: 262144 configured tokens.
BF16 weights: 68.0 estimated decimal GB, not runtime VRAM.