For pranksters, there is no better holiday than April Fools' Day. Celebrated every April 1, it is the one day of the year when harmless tricks are not just allowed — they are expected. Some historians believe the fun tradition began in 1582, when Europe switched from the Julian calendar to the Gregorian calendar. The new calendar moved New Year's Day from April 1 to January 1. People who continued celebrating the New Year on April 1 were teased. Others think it started simply as a way to welcome spring.

Today, April Fools' Day is celebrated all over the world. Even companies join in the fun with clever pranks that often trick people for hours — and sometimes even days. Here are a few of our favorite pranks from past years.

Language-learning app Duolingo is famous for its April Fools' pranks. In 2025, the company announced a five-year cruise in partnership with Carnival Cruise Line. The imaginary trip promised stops in 195 countries across all seven continents, with passengers learning 40 languages along the way. A video showed travelers taking daily language lessons on board using the app. If they missed a day of practice, the company’s green owl mascot might even toss them off the ship. The announcement looked surprisingly real — until people realized it was released on April 1!

On April 1, 2025, ElevenLabs, an AI audio company, got dog owners excited with a new app. Called Text-to-Bark, it promised to turn human words into realistic dog barks. All users had to do was type a command and pick a dog breed. A cheeky promotional video even showed people holding full conversations with their dogs. Alas, it was just an April Fools’ joke.

In 2012, Canadian airline WestJet pulled off a hilarious April Fools' stunt with a video called "Kargo Kids." The spoof promised stressed parents a peaceful, "child‑free" flight. In the video, children were checked in and sent down a baggage conveyor to a special area in the cargo hold, while the parents relaxed in the passenger cabin. The realistic video remains one of WestJet’s most memorable pranks to-date.

Penguins are known to be flightless birds. However, on April 1, 2008, the BBC reported the discovery of a colony of flying Adélie penguins on Antarctica's King George Island. They even released a video showing the airborne birds. The news had the world buzzing with excitement. It was only a few days later, when the BBC released a follow-up video explaining the penguin "flight," that people realized it was a prank.

Resources: WestJet.com, Businessinsider.com, Wikipedia.org