★A blue whale's tongue can weigh as much as an elephant.★The Great Wall of China is not visible from space with the naked eye.★Most 'silver' spoons are actually made of stainless steel.★The longest hiccuping spree lasted 68 years.★Sloths only poop about once a week.★Pineapples take about two years to grow.★There are more stars in the universe than grains of sand on every beach on Earth.★Bees can recognize individual human faces.★Sharks existed on Earth before trees did.★Cows have best friends and get stressed when separated.★Pigeons can recognize themselves in a mirror.★If you lift a kangaroo's tail off the ground it can't hop.★A snail can sleep for three years straight.★Pteronophobia is the fear of being tickled by feathers.★Hot water freezes faster than cold water. This is called the Mpemba effect.★Peanuts aren't nuts, they are legumes.★A cloud can weigh more than a million pounds.★Humans are the only animals that blush.★Your tongue print is as unique as your fingerprint.★Bananas are berries, but strawberries are not.★Horses physically cannot vomit.★A day on Mercury lasts 59 Earth days.★A lion's roar can be heard from up to 5 miles away.★The 'new car smell' is made of dozens of chemicals off-gassing from the interior.★Sea otters hold hands while sleeping so they don't drift apart.★A group of crows mobbing a predator is literally called a 'murder patrol'.★Bubble wrap was originally invented as wallpaper.★A newborn kangaroo is about the size of a jellybean.★Nintendo was founded in 1889 as a playing card company.★Butterflies taste with their feet.★Honey never spoils. Archaeologists found 3000-year-old honey in Egyptian tombs that was still edible.★Octopuses have three hearts and blue blood.★There is a village in Norway called 'Hell' that freezes over every winter.★There are only two countries in the world whose names start with 'The': The Gambia and The Bahamas.★Banging your head against a wall for one hour burns 150 calories.★The smell of rain has a name: petrichor.★Sloths can hold their breath longer than dolphins can.★Google processes more than 8.5 billion searches every single day.★The microwave oven was invented by accident when a researcher noticed a chocolate bar melted in his pocket.★The average person walks the equivalent of three times around the world in a lifetime.★In Switzerland it is illegal to own just one guinea pig.★A blue whale's heart is roughly the size of a small car.★The Statue of Liberty was originally intended to be a lighthouse.★Saturn would float if you could find an ocean big enough.★Humans share 60% of their DNA with bananas.★Dolphins sleep with one eye open.★A group of jellyfish is called a smack.★A hippo's sweat is pink.★A mosquito has 47 teeth.★Elephants are the only mammals that can't jump.★Your nose can remember 50,000 different scents.★A flock of crows is known as a murder.★Your stomach gets a new lining every 3 to 4 days, otherwise it would digest itself.★A snail can have up to 25,000 teeth on its tongue.★Crows can recognize human faces and hold grudges for years.★A group of pandas is called an embarrassment.★A group of ferrets is called a business.★Cotton candy was co-invented by a dentist.★So far, two diseases have successfully been eradicated: smallpox and rinderpest.★A shrimp's heart is located in its head.★A newborn panda is smaller than a mouse.★The shortest war in history lasted 38 to 45 minutes between Britain and Zanzibar.★7% of American adults believe that chocolate milk comes from brown cows.★The inventor of the Pringles can is buried in one.★Cows have regional accents, they moo differently in different areas.★The first computer mouse was made of wood.★The average person spends six months of their life waiting for red lights to turn green.★Scotland's national animal is the unicorn.★A crocodile can't stick its tongue out.★The Hawaiian alphabet has only 13 letters.★Tigers have striped skin, not just striped fur.★A 'moment' was medieval unit of time equal to 90 seconds.★The fear of long words is ironically called hippopotomonstrosesquippedaliophobia.★The world's oldest known recipe is for beer.★The shortest commercial flight in the world lasts just 57 seconds.★A jiffy is an actual unit of time: 1/100th of a second.★A hummingbird's heart can beat up to 1,260 times per minute.★The Eiffel Tower can grow up to 6 inches taller during summer.★The human brain uses about 20% of the body's total energy.★A day on Venus is longer than a year on Venus.★Dragonflies have been around for about 300 million years.★Humans blink about 15 to 20 times per minute.★We have mapped more of Mars than of our own ocean floor.★The moon has moonquakes.★Bananas are curved because they grow towards the sun.★The French language has 13 different words for 'kiss'.★Ostriches can run faster than horses.★Hippos can't actually swim, they walk along the riverbed.★It takes about eight minutes for sunlight to reach Earth.★A 'jiffy' is one trillionth of a second in physics.★A day on Jupiter lasts only about 10 hours.★A group of frogs is called an army.★You can hear a blue whale's heartbeat from more than two miles away.★A group of owls is called a parliament.★A rhinoceros' horn is made of keratin, the same stuff as hair.★29th May is officially Put a Pillow on Your Fridge Day.★The first oranges weren't orange, they were green.★Chewing gum while you chop onions helps keep you from crying.★Avocados are toxic to most animals except humans.★Snakes can help predict earthquakes.★Vincent van Gogh only sold one painting during his lifetime.★Koalas have fingerprints nearly identical to humans.★The oldest 'your mom' joke was discovered on a 3,500 year old Babylonian tablet.★Ancient Egyptians slept on stone pillows.★Wombat poop is cube-shaped.★Dolphins have names for each other.★A group of porcupines is called a prickle.★Starfish can regenerate their lost limbs.★Ketchup was once sold as medicine in the 1830s.★Goldfish can recognize human faces.★Antarctica is the only continent without native reptiles or snakes.★Cherophobia is an irrational fear of fun or happiness.★The Mona Lisa has no eyebrows or eyelashes.★There are more than 1,000 chemicals in a cup of coffee.★An octopus has nine brains.★Cashews grow on the outside of a fruit, not inside a shell.★A bolt of lightning is five times hotter than the surface of the sun.★A group of flamingos is called a 'flamboyance'.★The dot over the letter 'i' is called a tittle.★The Dutch were once the tallest people in the world.★The smell of freshly cut grass is actually a plant distress signal.★The first item ever sold on eBay was a broken laser pointer.★Sea cucumbers breathe through their butts.★Polar bears have black skin under their white fur.★More than half of all people alive today have never made a phone call.★Rats laugh when tickled.★It is physically impossible to hum while holding your nose.★Barbie's full name is Barbara Millicent Roberts.★Voice actors for Mickey and Minnie Mouse got married in real life.★Cats can't taste sweetness.★There's a species of jellyfish that is immortal.★Octopuses can taste with their arms.★Cleopatra lived closer in time to the Moon landing than to the building of the Great Pyramid.★Pigs can't look up at the sky without rolling over.★The longest recorded flight of a chicken lasted 13 seconds.★There are more possible iterations of a game of chess than atoms in the observable universe.

★A blue whale's tongue can weigh as much as an elephant.★The Great Wall of China is not visible from space with the naked eye.★Most 'silver' spoons are actually made of stainless steel.★The longest hiccuping spree lasted 68 years.★Sloths only poop about once a week.★Pineapples take about two years to grow.★There are more stars in the universe than grains of sand on every beach on Earth.★Bees can recognize individual human faces.★Sharks existed on Earth before trees did.★Cows have best friends and get stressed when separated.★Pigeons can recognize themselves in a mirror.★If you lift a kangaroo's tail off the ground it can't hop.★A snail can sleep for three years straight.★Pteronophobia is the fear of being tickled by feathers.★Hot water freezes faster than cold water. This is called the Mpemba effect.★Peanuts aren't nuts, they are legumes.★A cloud can weigh more than a million pounds.★Humans are the only animals that blush.★Your tongue print is as unique as your fingerprint.★Bananas are berries, but strawberries are not.★Horses physically cannot vomit.★A day on Mercury lasts 59 Earth days.★A lion's roar can be heard from up to 5 miles away.★The 'new car smell' is made of dozens of chemicals off-gassing from the interior.★Sea otters hold hands while sleeping so they don't drift apart.★A group of crows mobbing a predator is literally called a 'murder patrol'.★Bubble wrap was originally invented as wallpaper.★A newborn kangaroo is about the size of a jellybean.★Nintendo was founded in 1889 as a playing card company.★Butterflies taste with their feet.★Honey never spoils. Archaeologists found 3000-year-old honey in Egyptian tombs that was still edible.★Octopuses have three hearts and blue blood.★There is a village in Norway called 'Hell' that freezes over every winter.★There are only two countries in the world whose names start with 'The': The Gambia and The Bahamas.★Banging your head against a wall for one hour burns 150 calories.★The smell of rain has a name: petrichor.★Sloths can hold their breath longer than dolphins can.★Google processes more than 8.5 billion searches every single day.★The microwave oven was invented by accident when a researcher noticed a chocolate bar melted in his pocket.★The average person walks the equivalent of three times around the world in a lifetime.★In Switzerland it is illegal to own just one guinea pig.★A blue whale's heart is roughly the size of a small car.★The Statue of Liberty was originally intended to be a lighthouse.★Saturn would float if you could find an ocean big enough.★Humans share 60% of their DNA with bananas.★Dolphins sleep with one eye open.★A group of jellyfish is called a smack.★A hippo's sweat is pink.★A mosquito has 47 teeth.★Elephants are the only mammals that can't jump.★Your nose can remember 50,000 different scents.★A flock of crows is known as a murder.★Your stomach gets a new lining every 3 to 4 days, otherwise it would digest itself.★A snail can have up to 25,000 teeth on its tongue.★Crows can recognize human faces and hold grudges for years.★A group of pandas is called an embarrassment.★A group of ferrets is called a business.★Cotton candy was co-invented by a dentist.★So far, two diseases have successfully been eradicated: smallpox and rinderpest.★A shrimp's heart is located in its head.★A newborn panda is smaller than a mouse.★The shortest war in history lasted 38 to 45 minutes between Britain and Zanzibar.★7% of American adults believe that chocolate milk comes from brown cows.★The inventor of the Pringles can is buried in one.★Cows have regional accents, they moo differently in different areas.★The first computer mouse was made of wood.★The average person spends six months of their life waiting for red lights to turn green.★Scotland's national animal is the unicorn.★A crocodile can't stick its tongue out.★The Hawaiian alphabet has only 13 letters.★Tigers have striped skin, not just striped fur.★A 'moment' was medieval unit of time equal to 90 seconds.★The fear of long words is ironically called hippopotomonstrosesquippedaliophobia.★The world's oldest known recipe is for beer.★The shortest commercial flight in the world lasts just 57 seconds.★A jiffy is an actual unit of time: 1/100th of a second.★A hummingbird's heart can beat up to 1,260 times per minute.★The Eiffel Tower can grow up to 6 inches taller during summer.★The human brain uses about 20% of the body's total energy.★A day on Venus is longer than a year on Venus.★Dragonflies have been around for about 300 million years.★Humans blink about 15 to 20 times per minute.★We have mapped more of Mars than of our own ocean floor.★The moon has moonquakes.★Bananas are curved because they grow towards the sun.★The French language has 13 different words for 'kiss'.★Ostriches can run faster than horses.★Hippos can't actually swim, they walk along the riverbed.★It takes about eight minutes for sunlight to reach Earth.★A 'jiffy' is one trillionth of a second in physics.★A day on Jupiter lasts only about 10 hours.★A group of frogs is called an army.★You can hear a blue whale's heartbeat from more than two miles away.★A group of owls is called a parliament.★A rhinoceros' horn is made of keratin, the same stuff as hair.★29th May is officially Put a Pillow on Your Fridge Day.★The first oranges weren't orange, they were green.★Chewing gum while you chop onions helps keep you from crying.★Avocados are toxic to most animals except humans.★Snakes can help predict earthquakes.★Vincent van Gogh only sold one painting during his lifetime.★Koalas have fingerprints nearly identical to humans.★The oldest 'your mom' joke was discovered on a 3,500 year old Babylonian tablet.★Ancient Egyptians slept on stone pillows.★Wombat poop is cube-shaped.★Dolphins have names for each other.★A group of porcupines is called a prickle.★Starfish can regenerate their lost limbs.★Ketchup was once sold as medicine in the 1830s.★Goldfish can recognize human faces.★Antarctica is the only continent without native reptiles or snakes.★Cherophobia is an irrational fear of fun or happiness.★The Mona Lisa has no eyebrows or eyelashes.★There are more than 1,000 chemicals in a cup of coffee.★An octopus has nine brains.★Cashews grow on the outside of a fruit, not inside a shell.★A bolt of lightning is five times hotter than the surface of the sun.★A group of flamingos is called a 'flamboyance'.★The dot over the letter 'i' is called a tittle.★The Dutch were once the tallest people in the world.★The smell of freshly cut grass is actually a plant distress signal.★The first item ever sold on eBay was a broken laser pointer.★Sea cucumbers breathe through their butts.★Polar bears have black skin under their white fur.★More than half of all people alive today have never made a phone call.★Rats laugh when tickled.★It is physically impossible to hum while holding your nose.★Barbie's full name is Barbara Millicent Roberts.★Voice actors for Mickey and Minnie Mouse got married in real life.★Cats can't taste sweetness.★There's a species of jellyfish that is immortal.★Octopuses can taste with their arms.★Cleopatra lived closer in time to the Moon landing than to the building of the Great Pyramid.★Pigs can't look up at the sky without rolling over.★The longest recorded flight of a chicken lasted 13 seconds.★There are more possible iterations of a game of chess than atoms in the observable universe.

Reaction time

Best avg

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Reaction time

Test your reflexes. Click as fast as you can the moment the screen turns green.

Click or press space to start.

How to play Reaction time

Tap or click anywhere to start. The screen turns red and waits a random amount of time. The instant it turns green, click as fast as you can. Your reaction time appears in milliseconds. Click while the screen is still red and the round resets. Run five rounds and the average is your final score.

Tips

Rest your finger lightly, do not press into the trackpad
Watch the centre of the screen, not the edges
Eat first, sugar and caffeine both help short reactions
Five clean rounds is more honest than one lucky one

About Reaction time

Reaction tests are old psychology lab tools. Wilhelm Wundt was running them in the 1870s with mechanical timers and stop watches. Average human reaction time to a visual cue lands around 250 milliseconds. Below 200 is fast, below 150 is suspicious. Pilots, athletes and racing drivers all train to drop their numbers. Your phone or laptop adds about 30 milliseconds of input lag, so the real number is even faster than what you see.

More reflex games

Math sprint: Solve as many math sums as you can in 60 seconds.
Snake: A modern take on the classic. Don't bite your tail.
Aim trainer: Click as many targets as you can in 30 seconds.
Whack a mole: Bonk the moles before they pop back into their holes.
Stroop test: Read the colour, ignore the word. Brain twister in 30 seconds.
Color match: Tap when the two colours line up. Sounds simple, gets fast.

Browse the full arcade →

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0Pixels scrolled

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0Clicks made

0.00Calories burned

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