petKeeper is a Chrome add-on developed by tacchan5424 that allows users to virtually keep pets, such as dogs and cats, right in their browser. Initially, the pets are shy and wander aimlessly, but they gradually become more friendly and start following the user's mouse cursor as they are fed. Feeding the pets also results in them leaving behind waste that needs to be cleaned up.

The add-on offers a variety of pet options, including brown dogs and white cats, allowing users to choose the pet that suits their preference.

To feed the pets, users can place food on the screen by pressing Ctrl+Shift+E. The pets will go to eat when they are hungry, which can be determined by the green gauge located below the pet. Cleaning up the waste left by the pets can be done by simply clicking on it.

As users continue to feed the pets, they will gradually become more attached and start following the mouse cursor. The level of attachment can be determined by the light blue gauge located below the pet.

It is important to note that the pet types, status, and waste information are saved separately for each domain. For example, the information saved while using Chrome search pages will be different from that saved while using Gmail.