YOLOv3 🚀 is a family of object detection architectures and models pretrained on the COCO dataset, and represents Ultralytics open-source research into future vision AI methods, incorporating lessons learned and best practices evolved over thousands of hours of research and development.
Documentation
See the YOLOv3 Docs for full documentation on training, testing and deployment.
Quick Start Examples
Install
Python>=3.6.0 is required with all requirements.txt installed including PyTorch>=1.7:
$ git clone https://github.com/ultralytics/yolov3
$ cd yolov3
$ pip install -r requirements.txt
Inference
Inference with YOLOv3 and PyTorch Hub. Models automatically download from the latest YOLOv3 release.
import torch
# Model
model = torch.hub.load('ultralytics/yolov3', 'yolov3') # or yolov3-spp, yolov3-tiny, custom
# Images
img = 'https://ultralytics.com/images/zidane.jpg' # or file, Path, PIL, OpenCV, numpy, list
# Inference
results = model(img)
# Results
results.print() # or .show(), .save(), .crop(), .pandas(), etc.
Inference with detect.py
detect.py runs inference on a variety of sources, downloading models automatically from
the latest YOLOv3 release and saving results to runs/detect.
$ python detect.py --source 0 # webcam
img.jpg # image
vid.mp4 # video
path/ # directory
path/*.jpg # glob
'https://youtu.be/Zgi9g1ksQHc' # YouTube
'rtsp://example.com/media.mp4' # RTSP, RTMP, HTTP stream
Training

Tutorials
Environments
Get started in seconds with our verified environments. Click each icon below for details.
<a href="https://colab.research.google.com/github/ultralytics/yolov3/blob/master/tutorial.ipynb">
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</a>
<a href="https://www.kaggle.com/ultralytics/yolov3">
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</a>
<a href="https://hub.docker.com/r/ultralytics/yolov3">
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</a>
<a href="https://github.com/ultralytics/yolov3/wiki/AWS-Quickstart">
<img src="https://github.com/ultralytics/yolov5/releases/download/v1.0/logo-aws-small.png" width="15%"/>
</a>
<a href="https://github.com/ultralytics/yolov3/wiki/GCP-Quickstart">
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</a>
Integrations
<a href="https://wandb.ai/site?utm_campaign=repo_yolo_readme">
<img src="https://github.com/ultralytics/yolov5/releases/download/v1.0/logo-wb-long.png" width="49%"/>
</a>
<a href="https://roboflow.com/?ref=ultralytics">
<img src="https://github.com/ultralytics/yolov5/releases/download/v1.0/logo-roboflow-long.png" width="49%"/>
</a>
| Weights and Biases | Roboflow ⭐ NEW |
|---|---|
| Automatically track and visualize all your YOLOv3 training runs in the cloud with Weights & Biases | Label and export your custom datasets directly to YOLOv3 for training with Roboflow |
Why YOLOv5

YOLOv3-P5 640 Figure (click to expand)

Figure Notes (click to expand)
python val.py --task study --data coco.yaml --iou 0.7 --weights yolov5n6.pt yolov5s6.pt yolov5m6.pt yolov5l6.pt yolov5x6.pt|Model |size
(pixels) |mAPval
0.5:0.95 |mAPval
0.5 |Speed
CPU b1
(ms) |Speed
V100 b1
(ms) |Speed
V100 b32
(ms) |params
(M) |FLOPs
@640 (B) |--- |--- |--- |--- |--- |--- |--- |--- |--- |YOLOv5n |640 |28.4 |46.0 |45 |6.3|0.6|1.9|4.5 |YOLOv5s |640 |37.2 |56.0 |98 |6.4 |0.9 |7.2 |16.5 |YOLOv5m |640 |45.2 |63.9 |224 |8.2 |1.7 |21.2 |49.0 |YOLOv5l |640 |48.8 |67.2 |430 |10.1 |2.7 |46.5 |109.1 |YOLOv5x |640 |50.7 |68.9 |766 |12.1 |4.8 |86.7 |205.7 | | | | | | | | | |YOLOv5n6 |1280 |34.0 |50.7 |153 |8.1 |2.1 |3.2 |4.6 |YOLOv5s6 |1280 |44.5 |63.0 |385 |8.2 |3.6 |16.8 |12.6 |YOLOv5m6 |1280 |51.0 |69.0 |887 |11.1 |6.8 |35.7 |50.0 |YOLOv5l6 |1280 |53.6 |71.6 |1784 |15.8 |10.5 |76.8 |111.4 |YOLOv5x6
1536 |54.7
55.4 |72.4
72.3 |3136
|26.2
|19.4
|140.7
|209.8
-
Table Notes (click to expand)
Reproduce by python val.py --data coco.yaml --img 640 --conf 0.001 --iou 0.65
* Speed averaged over COCO val images using a AWS p3.2xlarge instance. NMS times (~1 ms/img) not included.
Reproduce by python val.py --data coco.yaml --img 640 --conf 0.25 --iou 0.45
* TTA Test Time Augmentation includes reflection and scale augmentations.
Reproduce by python val.py --data coco.yaml --img 1536 --iou 0.7 --augment
Contribute
We love your input! We want to make contributing to YOLOv3 as easy and transparent as possible. Please see our Contributing Guide to get started, and fill out the YOLOv3 Survey to send us feedback on your experiences. Thank you to all our contributors!
Contact
For YOLOv3 bugs and feature requests please visit GitHub Issues. For business inquiries or professional support requests please visit https://ultralytics.com/contact.
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$ claude mcp add yolov3 \
-- python -m otcore.mcp_server <graph>