Skip to main content
Metric names in W&B must follow GraphQL naming conventions to ensure they can be properly sorted and filtered in the UI.

​
Valid metric names

  • Allowed characters: Letters (A-Z, a-z), digits (0-9), and underscores (_)
  • Starting character: Names must start with a letter or underscore
  • Pattern: Metric names should match /^[_a-zA-Z][_a-zA-Z0-9]*$/
Metrics that don’t follow these rules may not be sortable or filterable in the W&B UI.

​
Examples

Valid metric names: 
with wandb.init() as run:
  run.log({"accuracy": 0.9, "val_loss": 0.1, "epoch_5": 5})
  run.log({"modelAccuracy": 0.95, "learning_rate": 0.001})
Invalid metric names (avoid these): 
with wandb.init() as run:
  run.log({"acc,val": 0.9})  # Contains comma
  run.log({"loss-train": 0.1})  # Contains hyphen
  run.log({"test acc": 0.95})  # Contains space
  run.log({"5_fold_cv": 0.8})  # Starts with number
Replace invalid characters with valid characters such as underscores:
  • Instead of "test acc", use "test_acc"
  • Instead of "loss-train", use "loss_train"
  • Instead of "acc,val", use "acc_val"
For more information, see Metric naming constraints.
Experiments Metrics