Model weights · SAM 2.1
Download SAM 2.1 weights
A promptable segmentation model with video memory: one click, box or mask segments an object and tracks it across frames in real time. Pick a size below and download the official .pt checkpoint in one click, with published accuracy, parameters and license all in view.
SAM 2.1 checkpoints, pick a size and download
A promptable segmentation model with video memory: one click, box or mask segments an object and tracks it across frames in real time.
| Model | Params | Size | Download |
|---|---|---|---|
SAM 2.1 tiny sam2.1_t.pt | 38.9M | 78 MB | |
SAM 2.1 small sam2.1_s.pt | 46M | ||
SAM 2.1 base+ sam2.1_b.pt | 80.8M | 162 MB | |
SAM 2.1 large sam2.1_l.pt | 224.4M |
Figures are published by the authors. Weights host: github.com. Clicking Download verifies the file and starts it straight from the official CDN.
How to load SAM 2.1 weights
Install the Ultralytics package, then point the loader at the checkpoint. It downloads automatically on first use, or you can pass the local path to the file you downloaded above.
pip install ultralyticsfrom ultralytics import SAM
# Downloads on first use, or pass a local path to your .pt file
model = SAM("sam2.1_t.pt")
results = model("image.jpg")About SAM 2.1
SAM 2 (Meta AI) extends the Segment Anything model to video with a streaming memory, so a single click, box or mask prompt segments and tracks objects across frames in real time. The 2.1 checkpoints below are the latest, most accurate release, integrated into Ultralytics with permissive Apache-2.0 licensing.
- Author
- Meta AI
- Released
- 2024
- Tasks
- Segment, Track
- Framework
- Ultralytics (PyTorch)
- Input size
- 1024px
- License
- Apache-2.0
More model weights to download
Each page lists every checkpoint with accuracy, parameters, license and a one-click download.
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Frequently asked questions
- How do I download SAM 2.1 weights?
- Click the Download button next to any variant in the table above; we verify the file and start it straight from the official CDN. You can also let the loader fetch it automatically on first use with `model = SAM("sam2.1_t.pt")`. All 4 SAM 2.1 checkpoints are hosted officially.
- Is SAM 2.1 free for commercial use?
- SAM 2.1 is released under Apache-2.0. Apache-2.0 is permissive and commercial-friendly: you can use it in closed-source products with attribution. Always confirm against the linked license text.
- Which SAM 2.1 model size should I use?
- Start with SAM 2.1 tiny, the smallest and fastest, ideal for prototyping, edge and CPU. Move up the ladder only when you need more accuracy and have the compute for it.