Google has often adopted a light-hearted approach in a variety of circumstances. The most popular instances of Google Humor are the April Fool Jokes. Google has had a tradition of perpetrating April Fool's Day hoaxes.

2000: Google MentalPlex
Google announced a new "MentalPlex" search technology that supposedly read the user's mind to determine what the user wanted to search for, thus eliminating the step of actually typing in the search query.

2002: Pigeon Rank
Google reveals the technology behind its PageRank System — PigeonRank. Google touts the benefits of this cost-effective and efficient means of ranking pages, and reassures readers that there is no animal cruelty involved in the process. The article makes many humorous references and puns based on computer terminology and how Google PageRank really works.

2004: Google Lunar/Copernicus Center
Fictitious job opportunities for a research center on the moon. Luna/X (a pun to Linux as well as a reference to the Windows XP visual style and Mac OS X) is the name of a new operating system they claimed to have created for working there.

2005: Google Gulp
Google Gulp, a fictitious drink, was announced by Google in 2005. According to the company, this beverage would optimize one's use of the Google search engine by increasing the drinker's intelligence. It was claimed this boost was achieved through real-time analysis of the user's DNA and carefully tailored adjustments to neurotransmitters in the brain (a patented technology termed Auto-Drink). The drink was said to come in "4 great flavors": Glutamate Grape (glutamic acid), Sugar-Free Radical (free radicals), Beta Carroty (beta carotene), and Sero-Tonic Water (serotonin).
This hoax was likely intended as a parody of Google's invite-only email service called Gmail. Although ostensibly free, the company claimed the beverage could only be obtained by returning the cap of a Google Gulp bottle to a local grocery store: a catch-22. In the Google Gulp FAQ, Google replies to the observation "I mean, isn't this whole invite-only thing kind of bogus?" by saying "Dude, it's like you've never even heard of viral marketing."

2006: Google Romance
On April Fool's Day 2006, Google Romance was announced on the main Google search page with the introduction, "Dating is a search problem. Solve it with Google Romance." It pretends to offer a "Soulmate Search" to send users on a "Contextual Date". A parody of online dating, it amusingly had a link for "those who generally favor the 'throw enough stuff at the wall' approach to online dating" to Post multiple profiles with a bulk upload file, you sleaze in addition to Post your Google Romance profile. Clicking on either of these gave an error page, which explained that it was an April Fool's joke and included links to previous April Fool's Jokes for nostalgia.