SAM 3 is a unified foundation model for promptable segmentation in images and videos. It can detect, segment, and track objects using text or visual prompts such as points, boxes, and masks. Compared to its predecessor SAM 2, SAM 3 introduces the ability to exhaustively segment all instances of an open-vocabulary concept specified by a short text phrase or exemplars. Unlike prior work, SAM 3 can handle a vastly larger set of open-vocabulary prompts. It achieves 75-80% of human performance on our new SA-CO benchmark which contains 270K unique concepts, over 50 times more than existing benchmarks.
This breakthrough is driven by an innovative data engine that has automatically annotated over 4 million unique concepts, creating the largest high-quality open-vocabulary segmentation dataset to date. In addition, SAM 3 introduces a new model architecture featuring a presence token that improves discrimination between closely related text prompts (e.g., “a player in white” vs. “a player in red”), as well as a decoupled detector–tracker design that minimizes task interference and scales efficiently with data.
Install additional dependencies for example notebooks or development:
bash
1# For running example notebooks2pip install -e ".[notebooks]"34# For development5pip install -e ".[train,dev]"
Getting Started
⚠️ Before using SAM 3, please request access to the checkpoints on the SAM 3
Hugging Face repo. Once accepted, you
need to be authenticated to download the checkpoints. You can do this by running
the following steps
(e.g. hf auth login after generating an access token.)
Basic Usage
python
1import torch
2#################################### For Image ####################################3from PIL import Image
4from sam3.model_builder import build_sam3_image_model
5from sam3.model.sam3_image_processor import Sam3Processor
6# Load the model7model = build_sam3_image_model()8processor = Sam3Processor(model)9# Load an image10image = Image.open("<YOUR_IMAGE_PATH.jpg>")11inference_state = processor.set_image(image)12# Prompt the model with text13output = processor.set_text_prompt(state=inference_state, prompt="<YOUR_TEXT_PROMPT>")1415# Get the masks, bounding boxes, and scores16masks, boxes, scores = output["masks"], output["boxes"], output["scores"]1718#################################### For Video ####################################1920from sam3.model_builder import build_sam3_video_predictor
2122video_predictor = build_sam3_video_predictor()23video_path ="<YOUR_VIDEO_PATH>"# a JPEG folder or an MP4 video file24# Start a session25response = video_predictor.handle_request(26 request=dict(27type="start_session",28 resource_path=video_path,29)30)31response = video_predictor.handle_request(32 request=dict(33type="add_prompt",34 session_id=response["session_id"],35 frame_index=0,# Arbitrary frame index36 text="<YOUR_TEXT_PROMPT>",37)38)39output = response["outputs"]
Examples
The examples directory contains notebooks demonstrating how to use SAM3 with
various types of prompts:
sam3_video_predictor_example.ipynb
: Demonstrates how to prompt SAM 3 with text prompts on videos, and doing
further interactive refinements with points.
There are additional notebooks in the examples directory that demonstrate how to
use SAM 3 for interactive instance segmentation in images and videos (SAM 1/2
tasks), or as a tool for an MLLM, and how to run evaluations on the SA-Co
dataset.
To run the Jupyter notebook examples:
bash
1# Make sure you have the notebooks dependencies installed2pip install -e ".[notebooks]"34# Start Jupyter notebook5jupyter notebook examples/sam3_image_predictor_example.ipynb
Model
SAM 3 consists of a detector and a tracker that share a vision encoder. It has 848M parameters. The
detector is a DETR-based model conditioned on text, geometry, and image
exemplars. The tracker inherits the SAM 2 transformer encoder-decoder
architecture, supporting video segmentation and interactive refinement.
Image Results
Model
Instance Segmentation
Box Detection
LVIS
SA-Co/Gold
LVIS
COCO
SA-Co/Gold
cgF1
AP
cgF1
cgF1
AP
AP
APo
cgF1
Human
-
-
72.8
-
-
-
-
74.0
OWLv2*
29.3
43.4
24.6
30.2
45.5
46.1
23.9
24.5
DINO-X
-
38.5
21.3
-
52.4
56.0
-
22.5
Gemini 2.5
13.4
-
13.0
16.1
-
-
-
14.4
SAM 3
37.2
48.5
54.1
40.6
53.6
56.4
55.7
55.7
* Partially trained on LVIS, APo refers to COCO-O accuracy
Video Results
Model
SA-V test
YT-Temporal-1B test
SmartGlasses test
LVVIS test
BURST test
cgF1
pHOTA
cgF1
pHOTA
cgF1
pHOTA
mAP
HOTA
Human
53.1
70.5
71.2
78.4
58.5
72.3
-
-
SAM 3
30.3
58.0
50.8
69.9
36.4
63.6
36.3
44.5
SA-Co Dataset
We release 2 image benchmarks, SA-Co/Gold and
SA-Co/Silver, and a video benchmark
SA-Co/VEval. The datasets contain images (or videos) with annotated noun phrases. Each image/video and noun phrase pair is annotated with instance masks and unique IDs of each object matching the phrase. Phrases that have no matching objects (negative prompts) have no masks, shown in red font in the figure. See the linked READMEs for more details on how to download and run evaluations on the datasets.
This project is licensed under the SAM License - see the LICENSE file
for details.
Acknowledgements
We would like to thank the following people for their contributions to the SAM 3 project: Alex He, Alexander Kirillov,
Alyssa Newcomb, Ana Paula Kirschner Mofarrej, Andrea Madotto, Andrew Westbury, Ashley Gabriel, Azita Shokpour,
Ben Samples, Bernie Huang, Carleigh Wood, Ching-Feng Yeh, Christian Puhrsch, Claudette Ward, Daniel Bolya,
Daniel Li, Facundo Figueroa, Fazila Vhora, George Orlin, Hanzi Mao, Helen Klein, Hu Xu, Ida Cheng, Jake Kinney,
Jiale Zhi, Jo Sampaio, Joel Schlosser, Justin Johnson, Kai Brown, Karen Bergan, Karla Martucci, Kenny Lehmann,
Maddie Mintz, Mallika Malhotra, Matt Ward, Michelle Chan, Michelle Restrepo, Miranda Hartley, Muhammad Maaz,
Nisha Deo, Peter Park, Phillip Thomas, Raghu Nayani, Rene Martinez Doehner, Robbie Adkins, Ross Girshik, Sasha
Mitts, Shashank Jain, Spencer Whitehead, Ty Toledano, Valentin Gabeur, Vincent Cho, Vivian Lee, William Ngan,
Xuehai He, Yael Yungster, Ziqi Pang, Ziyi Dou, Zoe Quake.