Google frequently inserts jokes and hoaxes into its products on April Fools' Day, which takes place on April 1.
Google's first April Fools' Day hoax, the MentalPlex hoax, invited users to project a mental image of what they wanted to find whilst staring at an animated gif. Several humorous error messages were then displayed on the search results page, all listed below:
An additional error message was included which converted all navigation text to German, but was scrapped after user complaints.
Google reveals the technology behind its PageRank Systems—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, (for example, a chart showing the pigeons' consumption of linseed and flax, represented as "Lin/Ax Kernels," a pun on the Linux kernel).
Fictitious job opportunities for a research center on the moon. Luna/X (a pun to Linux and the Latin word for moon, as well as a reference to both the Windows XP visual style and Mac OS X) is the name of a new operating system they claimed to have created for working at the research center.
Google also announced Gmail on April 1, with an unprecedented and unbelievable free 1 GB space, compared to e.g. Hotmail's 2 MB. The announcement of Gmail was written in an unserious jokey language normally seen in April Fools' jokes, tricking many into thinking that it was an April Fools' joke. In reality, it was a double fake, in that the announced product was serious.
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; as the "Google Gulp FAQ" suggests, partly through MAO inhibition). 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).