What was the name of Google's 2013 April Fools' prank that simulated smells?

Google’s 2013 April Fools’ prank that simulated smells was called Google Nose.

Google Nose was presented as a fictional search feature that added scents to selected items in the Google Knowledge Graph. Users were invited to click a “Smell” button and experience the supposed scent through a computer, laptop or mobile device.

The prank reflected Google’s style of combining a plausible product interface with an impossible technology. Its promotional material described a large database of smells and implied that devices could transmit aromas, even though ordinary computers and phones could not deliver scents in that way.

Google Nose is easy to confuse with genuine Google search features announced around the same period, including Knowledge Graph improvements and Google Maps experiments. It was not a commercial scent-delivery product; it was an April Fools’ hoax announced on April 1, 2013.