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Open-weight model · Image segmentation

sapiens2-seg-0.4b

by AI at Meta facebook/sapiens2-seg-0.4b

Per-pixel body-part segmentation with 29 classes (28 parts + background). This repository contains the 0.4B Body-Part Segmentation checkpoint, finetuned from the Sapiens2-0.4B pretrained backbone.

Parameters407M
Context
Weights3.3 GB
Licenseother
AccessOpen weights
Monthly Downloads37.9k

Runs On

What it takes to serve sapiens2-seg-0.4b (407M 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 0.8 GB 1.0 GB 1x MI300X (192 GB)
Vultr
$1.85 1x H100 $1.99 · 1x MI325X $2.00
8-bit 0.4 GB 0.5 GB 1x MI300X (192 GB)
Vultr
$1.85 1x H100 $1.99 · 1x MI325X $2.00
4-bit 0.2 GB 0.2 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 Sep 18, 2026.

Model Card

Per-pixel body-part segmentation with 29 classes (28 parts + background). This repository contains the 0.4B Body-Part Segmentation checkpoint, finetuned from the Sapiens2-0.4B pretrained backbone. Install the Sapiens2 repo (pip install -e.), download the checkpoint, and run the demo: See the Body-Part Segmentation guide for details on inputs, outputs, and visualization options. See the Sapiens2 Collection for all variants and other downstream task checkpoints. Released under the Sapiens2 License.

Excerpt from the card by AI at Meta, licensed other.

Configuration

Architecture
Sapiens2ForSemanticSegmentation
Layers
24
Hidden size
1,024
Feed-forward size
4,096
Attention heads
16
RoPE base
100
Model type
sapiens2

Identity and Version

Repository
facebook/sapiens2-seg-0.4b
Publisher
AI at Meta
Task
Image segmentation
Modality
Image
Library
sapiens2
Parameters
407M parameters
Languages
seg
Revision
449b3c5335e6722bb94990abdd1aa6e612432f22
First published
2026-04-23
Last updated
2026-06-15

Files and Weights

6 files, 3.3 GB in total. The weights are 2 files totalling 3.3 GB in safetensors.

Weights2 files · 3.3 GB
Configuration2 files · 4.4 KB
Documentation1 file · 3.3 KB
Repository1 file · 1.5 KB
Every file
FileTypeSizeSHA-256
model.safetensorsWeights1.6 GB b85fdb50b7d6
sapiens2_0.4b_seg.safetensorsWeights1.6 GB b85fdb50b7d6
config.jsonConfiguration3.9 KB
preprocessor_config.jsonConfiguration476 B
README.mdDocumentation3.3 KB
.gitattributesRepository1.5 KB

License and Download

License
other
Access
Open weights, no gate
Download size
3.3 GB
Download from AI at Meta

Released by AI at Meta through its official repository on Hugging Face. Read the license.

Built From

  • Derived from facebook/sapiens2-pretrain-0.4b
  • Described by arXiv:2604.21681

Memory Requirements

PrecisionWeights in memory
As published3.3 GB
16-bit0.8 GB
8-bit0.4 GB
4-bit0.2 GB

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

Questions About sapiens2-seg-0.4b

How much GPU memory does sapiens2-seg-0.4b need?

About 1 GB at 16-bit and 0.2 GB at 4-bit: the weights (407M parameters) plus a working margin. A long context needs more.

What is the cheapest GPU to run sapiens2-seg-0.4b 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 sapiens2-seg-0.4b released under?

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

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