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Open-weight model · Text generation

h2o-lightning-4b-nemotron-nano

by H2O.ai h2oai/h2o-lightning-4b-nemotron-nano

h2o-lightning-4b-nemotron-nano is an open-weight model for text generation from H2O.ai, released under other. It has 4B parameters and a 262,144-token context. At 16-bit it needs about 9.5 GB of GPU memory, which fits on 1x MI300X from $1.85 an hour, at the lowest prices in the SAVRN Index. It draws 1k downloads a month.

H2O-Lightning-4B-Nemotron-Nano is a 4B-parameter decision model from H2O.ai, built on nvidia/NVIDIA-Nemotron-3-Nano-4B-BF16. It answers typed decision questions about a record (a document, a ticket, a policy, a conversation).

Parameters4B
Context262,144
Weights7.9 GB
Licenseother
AccessOpen weights
Monthly Downloads1k

Runs On

What it takes to serve h2o-lightning-4b-nemotron-nano (4B parameters): the memory its weights need at each precision, and the cheapest way to rent enough data-center GPUs to hold them.

PrecisionWeightsMemory neededCheapest setupPer hourAlso fits
16-bit 7.9 GB 9.5 GB 1x MI300X (192 GB)
Vultr
$1.85 1x H100 $1.99 · 1x MI325X $2.00
8-bit 4.0 GB 4.8 GB 1x MI300X (192 GB)
Vultr
$1.85 1x H100 $1.99 · 1x MI325X $2.00
4-bit 2.0 GB 2.4 GB 1x MI300X (192 GB)
Vultr
$1.85 1x H100 $1.99 · 1x MI325X $2.00

Memory is the weights at that precision plus 20% for the runtime and a short context; a long context needs more. Prices are the lowest on-demand hourly rates in the SAVRN Index, read Oct 19, 2026.

h2o-lightning-4b-nemotron-nano on every accelerator the SAVRN Index prices, at every precision

Model Card

H2O-Lightning-4B-Nemotron-Nano is a 4B-parameter decision model from H2O.ai, built on nvidia/NVIDIA-Nemotron-3-Nano-4B-BF16. It answers typed decision questions about a record (a document, a ticket, a policy, a conversation). It returns a probability for - yes/no (noul): gives the probability that a statement is true; It reads text only. It runs on unmodified vLLM 0.30.0 with a small shim in front (lightningnemo4bshim.py). Each decision is one forward pass and one output token, so the cost is input tokens only. card. Every measurement on this card is this model's own. Measured with serve.sh as shipped (vLLM 0.30.0; one temperature, 0.75, for every question type), on one NVIDIA H100 80GB…

Excerpt from the card by H2O.ai, licensed other.

Configuration

Architecture
NemotronHForCausalLM
Context length (tokens)
262,144
Layers
42
Hidden size
3,136
Feed-forward size
12,544
Attention heads
40
Key/value heads
8
Head dimension
128
Vocabulary size
131,072
Stored precision
bfloat16
Model type
nemotron_h

Identity and Version

Repository
h2oai/h2o-lightning-4b-nemotron-nano
Publisher
H2O.ai
Task
Text generation
Modality
Text
Library
transformers
Parameters
4B parameters
Languages
jev
Revision
9901d77f57f0fefff1197375541e8c5739eca7e1
First published
2026-10-09
Last updated
2026-10-17

Files and Weights

24 files, 8.0 GB in total. The weights are 1 file totalling 7.9 GB in safetensors.

Weights1 file · 7.9 GB
Configuration11 files · 244.4 KB
Tokenizer2 files · 17.3 MB
Documentation5 files · 39.5 KB
Other4 files · 188.6 KB
Repository1 file · 1.6 KB
Every file
FileTypeSizeSHA-256
model.safetensorsWeights7.9 GB 4c62e5923170
assets.pyConfiguration9.7 KB —
box.pyConfiguration19.0 KB —
config.jsonConfiguration1.5 KB —
generation_config.jsonConfiguration171 B —
lightning_nemo4b_shim.pyConfiguration109.3 KB —
selector_v2.pyConfiguration17.4 KB —
serve_config.jsonConfiguration5.3 KB —
special_tokens_map.jsonConfiguration420 B —
state_cut.pyConfiguration7.5 KB —
test_security.pyConfiguration10.0 KB —
test_shim.pyConfiguration64.1 KB —
LICENSEDocumentation7.8 KB —
LICENSE-Apache-2.0Documentation11.6 KB —
LICENSE-cygnetDocumentation1.1 KB —
NOTICEDocumentation1.9 KB —
README.mdDocumentation17.0 KB —
assets/datamix.pngOther113.5 KB 01ef5917df3a
assets/qtype.pngOther62.8 KB —
chat_template.jinjaOther10.5 KB —
serve.shOther1.9 KB —
.gitattributesRepository1.6 KB —
tokenizer.jsonTokenizer17.1 MB 623c34567aeb
tokenizer_config.jsonTokenizer188.0 KB —

License and Download

License
other
Access
Open weights, no gate
Download size
7.9 GB
Download from H2O.ai

Released by H2O.ai through its official repository on Hugging Face.

Built From

Memory Requirements

PrecisionWeights in memory
As published7.9 GB
16-bit7.9 GB
8-bit4.0 GB
4-bit2.0 GB

Weights only, from the published parameter count; the key-value cache and runtime add to this.

Questions About h2o-lightning-4b-nemotron-nano

How much GPU memory does h2o-lightning-4b-nemotron-nano need?

About 9.5 GB at 16-bit and 2.4 GB at 4-bit: the weights (4B parameters) plus a working margin. A long context needs more.

What is the cheapest GPU to run h2o-lightning-4b-nemotron-nano on?

At 16-bit, 1x MI300X from $1.85 an hour; at 4-bit, 1x MI300X from $1.85 an hour, at the lowest on-demand prices the SAVRN Index lists.

What license is h2o-lightning-4b-nemotron-nano released under?

other, as its publisher declares it. Read the license text before commercial use.

What is h2o-lightning-4b-nemotron-nano's context length?

262,144 tokens, from the maximum position embeddings in its published configuration.

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