Classes are a way to identify your items and instances. You can categorize them further by using Attributes, which can be made mandatory based on your needs.

You can create an Object class, which is used for object instances, and you can create a Tag class, which is used to classify items as a whole. Learn more.

Assign classes or attributes

When in the Image Editor, you can assign a class to the item you’re looking at. You may also assign attributes, if the class has any.

You can assign a class in a number of ways.

Method 1

  1. In the Image Editor, create an instance with any annotation tool (except the Free text tag).
  2. Right-click the instance to open up a menu or find the instance in the Right panel.
  3. Select a class from the dropdown.
  4. Select attributes, if applicable.

Method 2
Select a class from the Default class feature in the left panel before you annotate. Your annotation tools will now automatically assign the selected class to any new instances you create.

Method 3

  1. In the Image Editor, select the Eyedropper tool. (If you can’t see it, press I on the keyboard or right-click on the Free text tag tool to find it).
  2. Click on the instance that has a class you want to replicate. The Eyedropper tool will change to the Bucket tool.
  3. With the Bucket, click on the instances you want to assign the selected class to.


  • After you’ve used the Bucket tool, if you switch to other tools then back to the Bucket, it will keep using the last class you selected with the Eyedropper.
  • You can manually switch to the Bucket tool from the left panel, or by pressing B on the keyboard.

Change a class or attribute

You can change a class or attribute by right-clicking the instance or finding it in the right panel. From the class/attribute dropdown, select a different option.

Remove a class or attribute

To remove a class or attribute:

  1. Right-click the instance you want to change, or find it in the right panel.
  2. Click the X corresponding to the class name or attribute to remove it.