Difference Between Crocodiles and Alligators

By Particia Yovane. December 13, 2022
Difference Between Crocodiles and Alligators

Alligators and crocodiles are easily confused because they belong to the same phylogenetic order. Also, both are large reptiles with tough skin, long tails, stubby legs, elongated snouts, and large teeth. Both have been around for a very long time, 83 million years, and have changed little since then. However, both reptiles have different distinct features that can help you figure out which one is which. Let us take a look at the characteristics of the two animals, so you can learn how to tell an alligator from a crocodile.

The following thedailyECO article explains the differences between a crocodile and an alligator, as well as some of their main characteristics.

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Differences between crocodiles and alligators

There are five key differences between a crocodile and an alligator that can help us distinguish these large reptiles:


This is the most immediate and easiest way to tell an alligator from a crocodile, even from a distance. Crocodiles have a long and sharp snout that is narrow and shaped like a V when we look at it from above. Alligators, on the other hand, have a more rounded, U-shaped snout.

In addition, the lower jaw of alligators is narrower than the upper jaw, so that when the mouth is closed, the upper jaw hides the lower teeth. In crocodiles, both jaws are the same size, so when the mouth is closed, we can see both the upper and lower teeth distributed in the different maxillary sinuses. This makes them look much more menacing, even with their mouths closed.


Crocodiles are usually much larger than alligators. This also depends on the state of maturation of each individual and the specific species, but as a general rule, when faced with two adults, the crocodile will be larger and heavier.


The skin of an alligator has smaller scales that are smoother than those of a crocodile. Some of the scales are arranged chaotically, with the largest in the center and the smallest on the outer sides. In a crocodile, the scale pattern is more symmetrical, with uniform rectangular scales. In crocodile skin, you can see a small hole near the edge of each scale, which is the remnant of a hair follicle. Alligators do not have pores.


Crocodiles live in both fresh and salt water, while alligators prefer freshwater environments. Crocodiles can survive in salt water because they are able to filter excess salinity. Alligators' glands, which are responsible for this function, are not as effective.


Crocodiles are often considered much more aggressive than alligators. While you should avoid contact with either animal at all costs, in general alligators are more docile than crocodiles and will only attack when hungry or provoked.

Difference Between Crocodiles and Alligators - Differences between crocodiles and alligators

Similarities between crocodiles and alligators

These are the main similarities between crocodiles and alligators:

  • Because alligators and crocodiles have similar jaws and teeth and are similar in size, they eat most of the same foods. Younger animals eat insects, crustaceans, and small fish. As they grow larger, they eat larger animals, but prefer animals they can consume in one or two bites. This is because their jaws cannot move sideways, which means these reptiles cannot crush their food with a traditional chewing motion.

  • Both are members of the crocodile family (Crocodylidae).

  • Both are reptiles, which means they are cold-blooded animals.

  • They cannot regulate their own internal body temperature and rely on external heat sources such as the sun.

  • Both alligators and crocodiles live in wetlands and along the coast, and both animals are amazingly fast swimmers.

  • Both crocodiles and alligators have existed relatively unchanged for 55 million years and have similar ancestors that first appeared 200 million years ago.

  • Among the many physical similarities is that both animals have eyes located on the top of their heads. This allows them to keep an eye out for prey while they are primarily underwater.

Main characteristics of crocodiles

The following are some interesting facts about crocodiles:

  • In the order Crocodilia, only the animals of the family Crocodylidae are called true crocodiles.

  • They are semi-aquatic predators that hunt opportunistically and usually hide in the water waiting for their prey. They then kill them by shaking them against the water or, if they are very large, dragging them to the bottom to drown them.

  • Among them is the Crocodylus porosus or Saltwater crocodile, the largest living reptile on earth, which can grow over 8 meters long and weigh 1,700 kg. You can see one in the picture below.

  • Crocodiles also have the strongest bite in the animal kingdom, with a force of 268 kg per square centimeter, or 16,470 N.

  • Crocodiles actually produce tears when they eat their prey. However, this does not mean that they actually cry. The air displaced through the sinuses may mix with the tears in the crocodiles' tear glands, which empty into the eye.

  • Crocodiles live a very long time. The saltwater crocodile has an average life expectancy of 70 years. The Nile crocodile (Crocodylus niloticus) can live up to 100 years. The oldest crocodile kept in captivity, Freshie, lived to be 140 years old at Australia Zoo.
Difference Between Crocodiles and Alligators - Main characteristics of crocodiles

Main characteristics of alligators

    The following are some interesting facts about the alligator:

    • Alligators make up the family Alligatoridae.

    • They feed on fish, birds, mammals, and even insects or amphibians, because despite their size, they are animals that use their energy very efficiently, so they actually need very little food.

    • One of the strangest facts about alligators is that their sex is not determined by DNA, but by climate. Alligators are born male when the temperature in the nest is warm and female when it is cool.

    • Alligators are designed for speed, not endurance. They can run faster than most humans, but they cannot sustain that pace for long.

    • Like cats, alligators have a structure in the back of their eyes that reflects light to improve night vision. When you shine a flashlight on an alligator's eyes, they glow red.

    • A typical alligator has about 75 teeth at any given time. When the teeth wear down or fall out, they are replaced. Therefore, many of them may have about 3,000 teeth in their lifetime.

    • Unlike most reptiles, they take care of their young. Although they are considered fierce predators, they are known to take great care of their offspring.
    Difference Between Crocodiles and Alligators - Main characteristics of alligators

    Which is more dangerous, a crocodile or an alligator?

    We have already mentioned that crocodiles are much more aggressive than alligators because alligators are opportunistic feeders, meaning they are unlikely to hunt you unless provoked. As if this were not enough, crocodiles are also larger and heavier. Crocodiles are also faster swimmers. A marine crocodile, the largest of all crocodiles, can reach a speed of 43 km/h in the water.

    If you want to read similar articles to Difference Between Crocodiles and Alligators, we recommend you visit our Facts about animals category.

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