To run TensorBoard, use the following command:

tensorboard --logdir=path/to/log-directory

Where logdir points to the directory where serialized data is contained. If this directory contains subdirectories which also contain serialized data, TensorBoard will visualize the data from all of those runs. Once TensorBoard is running, navigate your web browser to localhost:6006 to view the TensorBoard and its associated data.

For those wanting or needing to learn more about TensorBoard, please check out the following tutorial at https://www.tensorflow.org/tensorboard/r1/summaries.