What is the difference between a crocodile and an alligator?

What is the difference between a crocodile and an alligator?

Written by: Cameron Ward

Published: 05/05/2020

Reading time: 4 mins

These creatures are incredibly similar-looking, but we promise that if you think you’ve spotted an alligator in Kakadu, you’ll quickly learn otherwise.

Alligators in Kakadu

Let’s set one thing straight: There are no alligators in Kakadu. In fact, there are no alligators in Australia full stop – only crocodiles. Crocodiles can live in either fresh or saltwater and are found across much of the top coast of Australia. Both fresh and saltwater crocodiles live throughout Kakadu National Park, so if you do happen to see one, make sure to ask your guide about which species it may be.

Differences between Alligator and Crocodile

  • Alligator

It’s no wonder alligators and crocodiles look so similar – they’re closely related. The large reptiles have many similarities, but their differences can be quite glaring when you know what to look for. Just maybe don’t use your new skills out in the wild. We’d much rather you didn’t get eaten by a large reptile.


You can watch crocodiles get fed on our Jumping Crocodiles Tour from Darwin

  • One of the easiest ways to identify a crocodile or alligator is your location. Alligators are only found in the United States and China, so unless you’re in a zoo or those countries, you can almost guarantee you’re looking at a crocodile.
  • Physical appearance

  • Crocodiles and alligators can be easily distinguished by looking at their physical attributes if you know what to search for.Crocodiles are the larger species and fully-grown will be up to a metre longer than even large alligators. They are also a lighter colour and have long, v-shaped snouts. This v-shaped snout also gives crocodiles a rather toothy grin. In fact, crocodiles are unable to close their long snouts to hide their teeth.Additionally, crocodiles are slower than alligators. While we don’t recommend getting into a running race with either animal, crocodiles larger size makes them somewhat slower.
  • Similarities

  • Alligator
  • Besides all of their clear differences, these prehistoric beasts also have several similarities. Both first appeared during the era of the dinosaurs. However, crocodiles first made an appearence in fossil record, around 90 million years ago, while calligators came later, around 65 million years ago.
  • The large reptiles have physical similarities, such as their webbed feet, which help them glide through water easily. They are also cold-blooded, meaning they do not generate body heat and can spend long periods of time submerged in cold water without repercussion.
  • Both animals lay eggs and both are strictly carnivorous, each hunting both in the water and on the land surrounding their marshy homes. Strong tails help to propel both creatures through the water, providing them with great speed and control of their movement. They may also opt to use their tail as part of their defence mechanism if they feel challenged or attacked.
  • Fun facts about alligators and crocodiles

  • They can’t sweat!

  • Saltwater crocodile
  • Like all other cold-blooded reptiles, both crocs and alligators can’t sweat or produce their own heat. That’s why the tropial climate of Australia  is such a haven for them. To cool off, they sit along the riverbank with their mouths open. They’re:

Only able to eat above ground

  • Freshwater crocodile

Though crocodiles and alligators often strike their prey from underwater, they can’t swallow below the surface. This means they have to lift up their prey in order to eat. However, crocodiles can open their mouths underwater to catch the prey. They have a valve at the bottom of their mouth which seals it off from their breathing path.

  • Fast movers

  • In the water, saltwater crocodiles and alligators can both reach speeds of up to 32 km/hour. While they can only maintain this impressive speed in short, sharp bursts, they are incredibly competent swimmers, able to travel longer distances at 11-14km/h. They’re both more comfortable in water than on land.

    Never fully asleep

  • Crocodile Sleeping
    Crocodile with one eye open
  • The legend that a croc sleeps with one eye open isn’t just a spooky story to scare tourists but in fact the truth. They do this by doing unihemispheric sleeping. This involves only shutting down one half of their brain and keeping the other alert to any nearby danger.

Related article: How do I get from Darwin to Kakadu?

Cameron Ward
Cameron Ward
Managing Director at Sightseeing Tours Australia

Cameron Ward turned his travel passion into a thriving Australian tourism business. Before he co-founded his own business, Sightseeing Tours Australia, he was enjoying being a Melbourne tour guide. Even now, Cameron delights in helping visitors from all around the world get the most out of their incredible Australian trip. You’ll see Cameron leading tours or writing about his favourite Australian places where he shares his local insights.