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YOLOv5 with Comet

This guide will cover how to use YOLOv5 with Comet

About Comet

Comet builds tools that help data scientists, engineers, and team leaders accelerate and optimize machine learning and deep learning models.

Track and visualize model metrics in real time, save your hyperparameters, datasets, and model checkpoints, and visualize your model predictions with Comet Custom Panels! Comet makes sure you never lose track of your work and makes it easy to share results and collaborate across teams of all sizes!

Getting Started

Install Comet

pip install comet_ml

Configure Comet Credentials

There are two ways to configure Comet with YOLOv5.

You can either set your credentials through enviroment variables

Environment Variables

export COMET_API_KEY=<Your Comet API Key>
export COMET_PROJECT_NAME=<Your Comet Project Name> # This will default to 'yolov5'

Or create a .comet.config file in your working directory and set your credentials there.

Comet Configuration File

api_key=<Your Comet API Key>
project_name=<Your Comet Project Name> # This will default to 'yolov5'

Run the Training Script

# Train YOLOv5s on COCO128 for 5 epochs
python --img 640 --batch 16 --epochs 5 --data coco128.yaml --weights

That's it! Comet will automatically log your hyperparameters, command line arguments, training and valiation metrics. You can visualize and analyze your runs in the Comet UI


Try out an Example!

Check out an example of a completed run here

Or better yet, try it out yourself in this Colab Notebook

Open In Colab

Log automatically

By default, Comet will log the following items


  • Box Loss, Object Loss, Classification Loss for the training and validation data
  • mAP_0.5, mAP_0.5:0.95 metrics for the validation data.
  • Precision and Recall for the validation data


  • Model Hyperparameters
  • All parameters passed through the command line options


  • Confusion Matrix of the model predictions on the validation data
  • Plots for the PR and F1 curves across all classes
  • Correlogram of the Class Labels

Configure Comet Logging

Comet can be configured to log additional data either through command line flags passed to the training script or through environment variables.

export COMET_MODE=online # Set whether to run Comet in 'online' or 'offline' mode. Defaults to online
export COMET_MODEL_NAME=<your model name> #Set the name for the saved model. Defaults to yolov5
export COMET_LOG_CONFUSION_MATRIX=false # Set to disable logging a Comet Confusion Matrix. Defaults to true
export COMET_MAX_IMAGE_UPLOADS=<number of allowed images to upload to Comet> # Controls how many total image predictions to log to Comet. Defaults to 100.
export COMET_LOG_PER_CLASS_METRICS=true # Set to log evaluation metrics for each detected class at the end of training. Defaults to false
export COMET_DEFAULT_CHECKPOINT_FILENAME=<your checkpoint filename> # Set this if you would like to resume training from a different checkpoint. Defaults to ''
export COMET_LOG_BATCH_LEVEL_METRICS=true # Set this if you would like to log training metrics at the batch level. Defaults to false.
export COMET_LOG_PREDICTIONS=true # Set this to false to disable logging model predictions

Logging Checkpoints with Comet

Logging Models to Comet is disabled by default. To enable it, pass the save-period argument to the training script. This will save the logged checkpoints to Comet based on the interval value provided by save-period

python \
--img 640 \
--batch 16 \
--epochs 5 \
--data coco128.yaml \
--weights \
--save-period 1

Logging Model Predictions

By default, model predictions (images, ground truth labels and bounding boxes) will be logged to Comet.

You can control the frequency of logged predictions and the associated images by passing the bbox_interval command line argument. Predictions can be visualized using Comet's Object Detection Custom Panel. This frequency corresponds to every Nth batch of data per epoch. In the example below, we are logging every 2nd batch of data for each epoch.

Note: The YOLOv5 validation dataloader will default to a batch size of 32, so you will have to set the logging frequency accordingly.

Here is an example project using the Panel

python \
--img 640 \
--batch 16 \
--epochs 5 \
--data coco128.yaml \
--weights \
--bbox_interval 2

Controlling the number of Prediction Images logged to Comet

When logging predictions from YOLOv5, Comet will log the images associated with each set of predictions. By default a maximum of 100 validation images are logged. You can increase or decrease this number using the COMET_MAX_IMAGE_UPLOADS environment variable.

env COMET_MAX_IMAGE_UPLOADS=200 python \
--img 640 \
--batch 16 \
--epochs 5 \
--data coco128.yaml \
--weights \
--bbox_interval 1

Logging Class Level Metrics

Use the COMET_LOG_PER_CLASS_METRICS environment variable to log mAP, precision, recall, f1 for each class.

--img 640 \
--batch 16 \
--epochs 5 \
--data coco128.yaml \

Uploading a Dataset to Comet Artifacts

If you would like to store your data using Comet Artifacts, you can do so using the upload_dataset flag.

The dataset be organized in the way described in the YOLOv5 documentation. The dataset config yaml file must follow the same format as that of the coco128.yaml file.

python \
--img 640 \
--batch 16 \
--epochs 5 \
--data coco128.yaml \
--weights \

You can find the uploaded dataset in the Artifacts tab in your Comet Workspace artifact-1

You can preview the data directly in the Comet UI. artifact-2

Artifacts are versioned and also support adding metadata about the dataset. Comet will automatically log the metadata from your dataset yaml file artifact-3

Using a saved Artifact

If you would like to use a dataset from Comet Artifacts, set the path variable in your dataset yaml file to point to the following Artifact resource URL.

# contents of artifact.yaml file
path: "comet://<workspace name>/<artifact name>:<artifact version or alias>"
Then pass this file to your training script in the following way

python \
--img 640 \
--batch 16 \
--epochs 5 \
--data artifact.yaml \

Artifacts also allow you to track the lineage of data as it flows through your Experimentation workflow. Here you can see a graph that shows you all the experiments that have used your uploaded dataset. artifact-4

Resuming a Training Run

If your training run is interrupted for any reason, e.g. disrupted internet connection, you can resume the run using the resume flag and the Comet Run Path.

The Run Path has the following format comet://<your workspace name>/<your project name>/<experiment id>.

This will restore the run to its state before the interruption, which includes restoring the model from a checkpoint, restoring all hyperparameters and training arguments and downloading Comet dataset Artifacts if they were used in the original run. The resumed run will continue logging to the existing Experiment in the Comet UI

python \
--resume "comet://<your run path>"

Hyperparameter Search with the Comet Optimizer

YOLOv5 is also integrated with Comet's Optimizer, making is simple to visualie hyperparameter sweeps in the Comet UI.

Configuring an Optimizer Sweep

To configure the Comet Optimizer, you will have to create a JSON file with the information about the sweep. An example file has been provided in utils/loggers/comet/optimizer_config.json

python utils/loggers/comet/ \
  --comet_optimizer_config "utils/loggers/comet/optimizer_config.json"

The script accepts the same arguments as If you wish to pass additional arguments to your sweep simply add them after the script.

python utils/loggers/comet/ \
  --comet_optimizer_config "utils/loggers/comet/optimizer_config.json" \
  --save-period 1 \
  --bbox_interval 1

Running a Sweep in Parallel

comet optimizer -j <set number of workers> utils/loggers/comet/ \

Visualizing Results

Comet provides a number of ways to visualize the results of your sweep. Take a look at a project with a completed sweep here