how to check if an object has no tag?

how do you check if an object has no tag?

It's impossible for a gameobject not to have a tag. If you haven't assigned one, the default value for the tag is "Untagged". (Which is sort of a lie, but eh.)

Every gameobject has a tag. The default tag is "Untagged" If you compare the current tag to "Untagged", you should get the desired result