What is the largest animal in the world? The blue whale. It grows up to about 30 metres long and commonly weighs up to about 150 tonnes, with the heaviest estimates near 190 tonnes. It is also the largest animal known to have ever lived, bigger than any dinosaur known. On land, the African savanna elephant takes the title.
The largest animals in the world at a glance
Size records depend on what you measure: length, height, or weight. A giraffe is the tallest animal, but it is nowhere near the heaviest. This table lists twelve record-breakers, and the sections that follow explain the stories behind them. All sizes are "up to" or "about" figures, because animals vary a lot.
| Animal | Record | Size | Where it lives |
|---|---|---|---|
| Blue whale | Largest animal ever | Up to about 30 m, commonly up to ~150 t | All oceans except the Arctic |
| Whale shark | Largest fish | Commonly up to ~12 m; up to ~20 t | Warm tropical and temperate seas |
| Giant squid | Huge deep-sea predator | Up to ~12–13 m with tentacles | Deep ocean |
| Colossal squid | Heaviest invertebrate | About 495 kg specimen | Deep Southern Ocean |
| African savanna elephant | Largest land animal | Bulls typically ~6 t; up to ~4 m at the shoulder | African savannas |
| Giraffe | Tallest animal | Males up to ~5.5–5.8 m | African savannas |
| Saltwater crocodile | Largest living reptile | Males over 6 m, over 1,000 kg | South and South-East Asia, northern Australia |
| Ostrich | Largest living bird | Up to ~2.7 m, ~150 kg | Africa |
| Polar bear | Largest land carnivore | Males typically 350–700 kg | Arctic |
| Chinese giant salamander | Largest amphibian | Up to ~1.8 m | Rivers and streams of China |
| Green anaconda | Heaviest snake | Up to ~100+ kg; ~5–6 m | South America |
| Capybara | Largest rodent | About 35–66 kg | South America |
1. Blue whale: the largest animal ever
The blue whale is the largest animal ever to have lived, so if you are asking for the biggest animal in the world today or in Earth’s whole history, the answer is the same. It reaches up to about 30 metres, which is longer than a basketball court at about 28 metres.
Weight is just as striking. Blue whales commonly weigh up to about 150 tonnes, and the heaviest estimates reach about 190 tonnes. That is more than any dinosaur known from fossils.
Its heart is enormous too. A specimen studied by the Royal Ontario Museum had a heart of more than 180 kilograms. That answers a common question: how big is a blue whale’s heart? Roughly the weight of a few adult humans.
Blue whales live in all oceans except the Arctic. They are a good example of why the sea supports giants: water holds up the body, so a whale does not need heavy legs to carry its weight. Krill swarms are packed with food, and they link into ocean food chains and food webs, where tiny organisms feed the largest animals on the planet.
The seas they swim in are salty, which matters for any marine animal’s body chemistry. If you want to know why, see how the salinity of the oceans works.
Is the blue whale bigger than dinosaurs? Yes, as far as fossils show. In 2023 scientists described a fossil whale, Perucetus colossus, and claimed it might rival the blue whale in weight. Later studies revised its estimated weight down, so the blue whale keeps its crown. Today the blue whale is listed as Endangered by the IUCN.
To picture the scale, compare it with a London double-decker bus, which is about 11 metres long. Try the tool below.
2. Whale shark: the largest fish
The whale shark is the largest fish in the sea. Commonly it reaches up to about 12 metres, and reliably measured animals have reached about 18 metres. The heaviest can weigh up to about 20 tonnes.
Like the blue whale, it is a filter feeder. It swims slowly with its mouth open and strains plankton and small fish from the water. That gentle diet makes it harmless to people, even though it is so big.
Whale sharks live in warm tropical and temperate seas. The IUCN listed the species as Endangered in 2016. So the largest fish, like the largest animal, is under pressure.
3. Giant squid and colossal squid
Deep in the dark ocean live two of the strangest giants on the list. They are the giant squid (Architeuthis) and the colossal squid (Mesonychoteuthis), and between them they hold some remarkable records for an animal with no backbone.
A giant squid can reach up to about 12–13 m in length, but that figure includes the two long feeding tentacles. Females are larger than males. Most of that length is arms and tentacles, so the body itself (the mantle) is much shorter than you might picture.
The eyes are the real showstopper. A giant squid’s eye can be up to about 27 cm across, roughly the size of a dinner plate. Together with the colossal squid, it has some of the largest eyes in the animal kingdom. In the near-darkness of the deep sea, a big eye gathers as much of the faint light as possible.
The colossal squid is the heavier of the two. A specimen caught in 2007 weighed about 495 kg, which makes the colossal squid the heaviest invertebrate known. If you are wondering about the largest invertebrate on Earth, this is the animal to name.
That second sighting is a useful reminder that even the biggest animals can stay hidden. The young colossal squid was tiny compared with the adults, so scientists still have a lot to learn about how these animals grow, feed and live.
Both squid are invertebrates. They have soft bodies, arms and tentacles instead of a skeleton, which is very different from the whales and fish you met earlier. Their size shows that being enormous does not need bones.
4. African elephant: the largest land animal
Now to dry land. The largest land animal is the African savanna (bush) elephant. Adult bulls typically weigh about 6 tonnes, and the heaviest record is about 10 tonnes. At the shoulder they stand up to about 4 m tall, taller than most rooms in a house.
Nothing else walking on land today comes close. That is why the elephant is the standard answer to “what is the biggest land animal?”, and why it leads any list of the largest animals in the world that live on land. If you want to compare it with its Asian cousin, our guide to African and Asian elephants sets out the differences side by side.
The trunk and the ears
An elephant’s trunk is a tool with many jobs. It is used for breathing, smelling, drinking and grabbing food, so it works as a nose, a straw and a hand in one.
The large ears do more than catch sound. Blood flows close to the surface of the thin skin, and the ears help the elephant release heat in hot weather. A huge body loses heat slowly, so big ears are a useful cooling system.
Life in the herd
Females and their young live in family herds led by a matriarch, usually an older female. Bulls spend more of their time apart from the herd. The leader’s knowledge of where to find food and water matters for the whole group.
Conservation status
In 2021 the IUCN assessed the two African elephant species separately for the first time. The savanna elephant was listed as Endangered, and the forest elephant as Critically Endangered. Poaching and habitat loss are among the main pressures, which is why protecting giants matters so much.
5. Giraffe: the tallest animal
If the elephant wins on weight, the giraffe wins on height. It is the tallest animal in the world, with males reaching up to about 5.5–5.8 m. That is taller than a single-storey house and taller than a London double-decker bus, which is about 4.3 m high.
The neck looks as if it must hold hundreds of bones, yet a giraffe has only 7 vertebrae, the same number as a human. Each one is simply extremely long. The tongue is long too, about 45–50 cm, which lets the giraffe wrap it around leaves high in the trees.
Height brings an engineering problem. The brain sits far above the heart, so the heart has to pump hard to push blood all the way up. A giraffe’s circulation is built to cope with that, and it is one of the best examples in nature of body shape matching a lifestyle.
One species or four?
For a long time, giraffes were treated as a single species. In August 2025 the IUCN’s Giraffe and Okapi Specialist Group officially recognised four giraffe species. This is a good example of science changing as researchers study animals more closely.
Comparing giants from different continents can be fun. If you are curious how the giraffe’s home continent compares with North America, take a look at our article on the largest animal in North America, where the American bison, the continent's largest land animal, takes centre stage.
6. Saltwater crocodile — the largest reptile
The saltwater crocodile is the largest living reptile on Earth. Adult males can exceed 6 metres in length and weigh over 1,000 kg, which is more than a small car. Females are much smaller than males.
Despite its name, this animal is not restricted to the sea. It lives in coastal waters, estuaries, rivers and fresh water across South and South-East Asia and northern Australia. It can also swim far out to sea, which helps explain why it is spread across such a wide area.
It is also a record-breaker for power. A 2012 study by Erickson and colleagues measured a bite force of about 16,460 newtons, the strongest bite force ever measured for a living animal. For comparison, that is many times the force of a human bite. A crocodile does not chew its food. It grips, drags and swallows, so a powerful bite matters more than sharp, slicing teeth.
Wondering how a crocodile differs from its cousin, the alligator? Snout shape, teeth and habitat all give clues, and our guide to crocodile vs alligator differences explains how to tell them apart.
7. Ostrich — the largest bird
The ostrich is the largest and heaviest living bird. It stands up to about 2.7 metres tall and can weigh up to about 150 kg. That is taller than most doorways and heavier than many adult humans.
An ostrich cannot fly. Instead, it has long, powerful legs built for running, and it can reach about 70 km/h. That makes it the fastest bird on land, and it holds its own in any list of speedy runners. If you want to see how it compares with cheetahs and other sprinters, take a look at the fastest animals in the planet.
Ostriches also lay the largest eggs of any living bird. Like all birds, they lay eggs with a hard shell, a way of reproducing shared with reptiles, many fish and some mammals. You can read about the variety of this strategy in our article on egg-laying animals and their evolution.
8. Polar bear and brown bear — the largest land carnivores
Earlier we met the elephant, the largest land animal overall. Among meat-eaters, two bears share the top spot. The polar bear and the brown bear, including the big Kodiak brown bears of Alaska, are the largest land carnivores.
Male polar bears typically weigh between 350 and 700 kg. Large Kodiak brown bears are similar in size, so it is hard to crown one clear winner. Both are powerful predators with thick fur and strong limbs.
Polar bears live on and around Arctic sea ice, where they hunt seals. Their size is a real advantage in the cold, because a large body loses heat more slowly than a small one. But the same sea ice is under pressure, and the IUCN lists the polar bear as Vulnerable.
- Polar bear: males typically 350–700 kg, Arctic sea-ice hunter, IUCN Vulnerable.
- Kodiak brown bear: large individuals are similar in weight to male polar bears.
9. Chinese giant salamander — the largest amphibian
The largest amphibian in the world is the Chinese giant salamander. It can grow to about 1.8 metres long, which is roughly the height of a tall adult. It spends its whole life in cool, clear mountain streams and rivers.
Its appearance is unusual. It has a wide, flat head, tiny eyes and wrinkled, mottled skin. It hunts mainly at night, relying on senses other than sight to find prey in the dark water.
Scientists have also changed how they classify it. Research published in 2019 split the Chinese giant salamander (genus Andrias) into several separate species. One of them, the South China giant salamander (Andrias sligoi), may be the largest of all.
This is a sad record to hold. These salamanders are Critically Endangered, mainly because of farming and overharvesting. A giant that survived for a very long time is now among the amphibians most in need of protection.
That completes our tour of the first nine giants. Next come more record-breakers, from snakes to rodents, and then the big question of why some animals grow so large.
10–12. More record-breakers
The big names get the headlines, but plenty of other animals hold size records in their own groups. Snakes, rodents and insects all have giants, and none of them is as large as a whale or an elephant. They are still well worth a place in your field notes.
Green anaconda and reticulated python: the heaviest and longest snakes
Two snakes share the top spots, and they win different prizes. The green anaconda is the heaviest snake. It can weigh up to 100 kg or more and reach about 5–6 m in length, with a thick, muscular body built for life in swamps and slow rivers.
The reticulated python is the longest snake, at over 6 m. It is slimmer than an anaconda, so it weighs less even though it is longer. If an exam asks which snake is heaviest and which is longest, remember that the anaconda is heavy and the python is long.
Be careful with extreme claims you may see online. Stories of 10 m monsters are rarely backed by measurements, so stick to figures from careful records.
Capybara: the largest rodent
The capybara is the largest rodent in the world, weighing about 35–66 kg. That is roughly the mass of a large dog. It is a relative of guinea pigs and lives in South America, usually close to water.
Rodents are the biggest group of mammals by number of species, and most of them are tiny. The capybara shows how far the group can stretch when an animal has plenty of food, water and space.
Goliath beetle and colossal squid: giants without a backbone
Invertebrates are animals with no backbone, and they hold some surprising records. Among insects, the goliath beetle is one of the heaviest. Its larvae can weigh up to about 100 g, which is more than a chocolate bar.
The biggest invertebrate overall lives in the deep sea. The colossal squid is the heaviest invertebrate, with one specimen from 2007 weighing about 495 kg. We met it alongside the giant squid earlier in this guide, including the first footage of one alive in the wild in March 2025.
Why do some animals grow so big?
Size records are not an accident. A few helpful conditions come together, and they explain why most giants live in the sea.
- Water supports body weight. A whale floats, so its skeleton does not have to hold up its whole mass against gravity.
- Filter feeding is efficient. Blue whales and whale sharks strain huge amounts of krill and plankton from the water, so they get a lot of food for little chasing.
- Big bodies lose heat slowly. A large animal has less surface area for its volume, so it stays warm more easily. An elephant has the opposite problem on hot days, which is why its large ears help it release heat.
- Few predators. Once an animal is huge, very little can hunt it as an adult.
On land, the limits are tougher. Heavier animals need thicker bones to bear the weight, and they have to get rid of heat as well. This is one reason the largest land animal, the elephant, is far smaller than the largest ocean animal.
Size is one of many adaptations in plants and animals. Each one helps a living thing survive in its own habitat.
Giants in danger
Being big does not make an animal safe. Many of the animals in this guide are under pressure from hunting and poaching, habitat loss, ship strikes, fishing bycatch and climate change. Large animals also breed slowly, so populations recover slowly once they fall.
| Animal | IUCN status |
|---|---|
| Blue whale | Endangered |
| Whale shark | Endangered (2016) |
| African savanna elephant | Endangered (2021) |
| African forest elephant | Critically Endangered (2021) |
| Polar bear | Vulnerable |
| Chinese giant salamander | Critically Endangered |
Record-breakers come in all forms, and not all of them are about size. If you enjoy this topic, read about the slowest animals of the world, or the rare, pale creatures in our guide to albino animals.
Guess the giant
Frequently asked questions about the largest animals
What is the largest animal in the world?
The blue whale is the largest animal in the world. It can grow up to about 30 m long and commonly weighs up to about 150 tonnes, with the heaviest estimates around 190 tonnes. It lives in oceans around the world, except the Arctic, and feeds on krill.
What is the largest animal ever?
The blue whale is the largest animal known to have ever lived. It is bigger than any dinosaur known from fossils. A fossil whale called Perucetus colossus was once claimed to rival it in weight, but later studies revised that estimate down, so the blue whale still holds the record.
Is the blue whale bigger than a dinosaur?
Yes, the blue whale is bigger than any dinosaur known to science. Some long-necked dinosaurs were extremely large, but the blue whale is heavier, at up to about 150 tonnes commonly. Water supports its body, which helps explain why it can grow so large.
What is the largest land animal?
The African savanna elephant is the largest land animal. Bulls typically weigh about 6 tonnes and stand up to about 4 m at the shoulder, and the heaviest record is about 10 tonnes. Females and young live in family herds led by an older female called the matriarch.
What is the largest fish?
The whale shark is the largest fish. It is commonly up to about 12 m long, with reliable measurements up to about 18 m, and can weigh up to about 20 tonnes. Despite the name, it is a shark, not a whale, and it filters plankton and small fish from warm seas.
What is the largest reptile?
The saltwater crocodile is the largest living reptile. Males can exceed 6 m in length and weigh over 1,000 kg. It also has the strongest bite force ever measured, about 16,460 newtons, and lives in coastal and fresh water across South and South-East Asia and northern Australia.
What is the tallest animal?
The giraffe is the tallest animal, with males reaching up to about 5.5–5.8 m. Its neck has just seven vertebrae, the same number as a human, but each one is very long. In August 2025 the IUCN's Giraffe and Okapi Specialist Group recognised four giraffe species instead of one.
What is the largest bird?
The ostrich is the largest and heaviest living bird, standing up to about 2.7 m tall and weighing up to about 150 kg. It cannot fly, but it can run at about 70 km/h. It also lays the largest eggs of any living bird.
How big is a blue whale's heart?
A blue whale's heart can weigh more than 180 kg, based on a specimen held at the Royal Ontario Museum. That is roughly the mass of a few adult people put together. The heart has to pump blood around a body that can be up to about 30 m long.
