Try “planets”, “bees”, “volcano” or “angry”.
Big questions · Easy answers
Why is the sky blue? How do bees make honey? Ask a question and Ranki and Tanki explain it in easy words.
Pick a topic
40 questions in 8 topics, from the stars in the sky to the feelings in your tummy.
Your guides
Two best friends with one big hobby: asking questions. They are AI generated characters, and they love to explain things.
The question collector, 9
Hi, I am Ranki. I collect questions like other kids collect stickers. How does a plane stay up? Why does the Moon change shape? If something works, I want to know how. My favourite words are “let’s find out”.
The wonder finder, 10
Hello, I am Tanki. I love animals, storms, old castles and dinosaur bones. I always carry my magnifying glass, because the world is full of tiny wonders. And I love to start a sentence with “did you know”.
Start here
Six questions children ask again and again.
Sunlight looks white, but it hides every colour of the rainbow. Find out why the air sends the blue part to your eyes, and why sunsets turn orange.
Ranki explainsAges 6+4 min
Eight planets travel around our Sun, from tiny, scorching Mercury to cold, windy Neptune. Meet them all and learn a trick to remember their order.
Ranki explainsAges 8+4 min
Dinosaurs ruled the Earth for millions of years, then most of them vanished. Find out about the giant space rock, the dark sky and the dinosaurs still alive today.
Tanki explainsAges 6+5 min
Honey starts as a sweet juice inside flowers. Follow a busy worker bee from blossom to hive and find out how she turns nectar into honey.
Tanki explainsAges 6+4 min
A big passenger plane is heavier than a herd of elephants, yet it floats through the sky. Find out how wings, engines and air work together.
Tanki explainsAges 8+5 min
Deep under your feet, some rock is so hot that it melts. Find out how gas and pressure push it up until a volcano erupts, and how scientists keep people safe.
Tanki explainsAges 8+5 min
Fun & games
A quiz with stars, a trip to every planet, experiments for home and more.
All questions
40 questions. Choose a topic or scroll through them all.
The Sun is a star, and deep inside it something amazing happens all day and all night. Find out how the Sun makes its light and heat.
Ranki explainsAges 6+5 min
Sometimes the Moon is a thin smile, sometimes a big round plate. Find out what is really going on, and learn the names of the Moon’s phases.
Tanki explainsAges 6+4 min
Eight planets travel around our Sun, from tiny, scorching Mercury to cold, windy Neptune. Meet them all and learn a trick to remember their order.
Ranki explainsAges 8+4 min
Stars seem to sparkle and flicker at night. Find out how moving air makes starlight wobble, and why planets shine with a much steadier light.
Tanki explainsAges 6+4 min
Floating breakfasts, sleeping bags on the wall and 16 sunrises a day. Discover how astronauts eat, sleep, wash and stay strong on the space station.
Ranki explainsAges 8+4 min
Honey starts as a sweet juice inside flowers. Follow a busy worker bee from blossom to hive and find out how she turns nectar into honey.
Tanki explainsAges 6+4 min
That soft, rumbly sound is one of the cosiest noises in the world. Find out how cats make it, and why they do not only purr when they are happy.
Ranki explainsAges 6+4 min
You have to come up for air when you dive, but fish stay under water all day. Find out how gills pull the oxygen they need right out of the water.
Tanki explainsAges 6+4 min
Every autumn, millions of birds set off on amazing journeys. Find out why they leave, how they find their way, and which bird flies the furthest.
Ranki explainsAges 8+5 min
It is longer than two buses and heavier than any dinosaur scientists know of. Meet the blue whale, the true giant of our planet.
Tanki explainsAges 6+4 min
Sunlight looks white, but it hides every colour of the rainbow. Find out why the air sends the blue part to your eyes, and why sunsets turn orange.
Ranki explainsAges 6+4 min
All you need is sunshine, raindrops and the Sun at your back. Find out how tiny drops of water split white light into a bow of bright colours.
Tanki explainsAges 6+4 min
Rain is very old water on a trip that never ends. Follow a drop from a puddle up into the clouds and back down again, and see what the Sun has to do with it.
Ranki explainsAges 6+5 min
Deep under your feet, some rock is so hot that it melts. Find out how gas and pressure push it up until a volcano erupts, and how scientists keep people safe.
Tanki explainsAges 8+5 min
Plants never go shopping or hunting, yet they grow all day long. Find out how leaves turn sunlight, water and air into food, and give us oxygen as a gift.
Ranki explainsAges 8+4 min
Every night you switch off for hours, but your body and brain stay busy. Find out what happens while you sleep, why we dream and how much sleep children need.
Tanki explainsAges 6+4 min
Your heart is a hard-working muscle about the size of your fist. Find out how it pumps blood around your body, what makes the lub dub sound and how to feel your pulse.
Ranki explainsAges 8+4 min
Without bones you would flop like a jellyfish. Find out how your skeleton holds you up, keeps your brain and heart safe and works together with your muscles.
Tanki explainsAges 6+4 min
Your lunch goes on a long, twisty journey through your body. Follow it from your mouth to your tummy and beyond, and see how your body takes out the good parts.
Ranki explainsAges 8+5 min
A wobbly tooth is a sign that you are growing up. Find out why baby teeth fall out, what pushes them and how to look after your new teeth.
Tanki explainsAges 6+4 min
Your messages and photos zoom around the world in tiny pieces. Find out how the internet carries them, and how to stay safe while you explore.
Ranki explainsAges 8+5 min
A big passenger plane is heavier than a herd of elephants, yet it floats through the sky. Find out how wings, engines and air work together.
Tanki explainsAges 8+5 min
Robots build cars, clean floors and drive around on Mars. Find out what makes a machine a robot, and where the word robot comes from.
Ranki explainsAges 6+4 min
Flick a switch and the light comes on. Follow electricity on its long journey from the power station, along the grid and into your home.
Tanki explainsAges 8+5 min
Magnets pull without touching, and sometimes they push. Find out which things stick, what poles are, and why the whole Earth acts like a magnet.
Ranki explainsAges 6+4 min
Dinosaurs ruled the Earth for millions of years, then most of them vanished. Find out about the giant space rock, the dark sky and the dinosaurs still alive today.
Tanki explainsAges 6+5 min
Millions of heavy stones, no cranes and no lorries. Find out how the ancient Egyptians built the Great Pyramid, and who really did the hard work.
Ranki explainsAges 8+5 min
Fierce raiders with horned helmets? Not quite. Meet the real Vikings: farmers, traders and brilliant sailors who reached America long before Columbus.
Tanki explainsAges 8+5 min
Towers, moats and drawbridges sound exciting. But castles were also cold, smoky and a bit smelly. Step inside and meet the people who lived there.
Ranki explainsAges 6+5 min
The first writing was not a story or a poem. It was a list of sheep and grain. Find out where writing began and where our alphabet comes from.
Tanki explainsAges 8+5 min
Counting countries sounds easy, but it is a real puzzle. Find out why most lists say about 195, and which countries are the biggest and the tiniest.
Ranki explainsAges 8+5 min
There are more than 7,000 languages on Earth. Find out how they grew apart, which ones are cousins, and how to say hello around the world.
Tanki explainsAges 6+4 min
Right now, some children are eating breakfast while others are fast asleep. Discover how a spinning Earth gives us day, night and time zones.
Ranki explainsAges 8+4 min
Uniforms or your own clothes, starting at 4 or at 7, lessons in a classroom or over the radio. Take a trip to schools around the world.
Tanki explainsAges 6+4 min
Africa, Antarctica, Asia, Australia, Europe, North America and South America. Meet the seven giant pieces of land on our planet, and the oceans in between.
Ranki explainsAges 6+4 min
Everybody feels angry sometimes, even grown-ups. Find out what anger does inside your body, and some calm, friendly ways to let it pass.
Tanki explainsAges 6+4 min
Listening, sharing, taking turns and saying sorry. Discover what makes a good friend, how to fix an argument and how to make new friends.
Ranki explainsAges 6+4 min
Giggles, chuckles and belly laughs. Find out why we laugh, why laughing is catching, which animals laugh too and why you cannot tickle yourself.
Tanki explainsAges 6+4 min
A fluttery tummy before a test, a show or a first day is very normal. Find out what your body is doing, and some simple ways to feel braver.
Ranki explainsAges 6+4 min
A smile, a thank you or a helping hand can brighten someone’s whole day. Discover why kindness matters, how it spreads and small kind ideas to try.
Tanki explainsAges 6+4 min
Good to know
rankitanki is a free knowledge website for children aged about 6 to 11. Ranki and Tanki answer big questions about space, animals, nature, the body, technology, history, the world and feelings, in easy English.
Ranki and Tanki are two friendly AI generated characters, not real children. Ranki loves space, machines and experiments. Tanki loves animals, nature and stories from long ago. Together they explain the world.
Yes. There is no sign-up, no chat, no comments and no cookies. The articles carry no adverts. Quiz stars are saved only in your own browser.
The rankitanki editorial team writes every answer and checks facts against reliable sources such as space agencies, museums and encyclopaedias before publishing.