H-Optimus-1 is current — a 1.1B-parameter vision transformer (ViT-g/14) trained with self-supervised learning on billions of tiles from over 1 million slides of more than 800,000 patients, spanning 50+ organs, 3 scanner types, and 4,000+ clinical centers. As of May 2026 it ranks #1 on the public PathBench leaderboard and is the top image-only model on HEST. H-Optimus-0 (2024) is the previous generation, open-source under Apache 2.0. See Benchmarks and the Hugging Face model details.

Specifications
| Property | Value |
|---|---|
| Task | Tile embedding |
| Input | 224×224 RGB tile at 0.5 µm/px |
| Output | 1536-dimensional feature vector |
| On-prem endpoint | POST /api/embed/h1 |
| SageMaker dispatch | model_name: "h1", mode: "embedding" |
| Recommended instance | ml.g5.xlarge |
How it’s used
Segment tissue
Run tissue segmentation to keep tissue-bearing tiles.
Extract features
Embed 224×224 tiles to get a 1536-d vector each (the SDK tiles and dispatches for you).
Deploy
H-Optimus runs on AWS SageMaker, on-premise, or Hugging Face (academic). See the Deployment overview for the full comparison and setup steps.Guides
Tile embeddings & PCA
Extract embeddings and visualize morphology.
Bioptimus SDK
Run whole-slide inference with the Bioptimus SDK.

