Alligator vs Crocodile: All 9 Differences Explained

Crocodiles and alligators are the closest animals we have to dinosaurs. They can be traced back to over 70 million years ago. Since then, these ‘living fossils’ have changed very little in appearance or behavior.

Alligators and crocodiles are similar to each other in size, behavior, and appearance. It can sometimes be quite difficult to tell them apart. This is especially true in the southern United States where both species live.

If a crocodilian has you confused, then fear not! There are many subtle but significant differences between alligators vs crocodiles.

This guide will teach you how to spot the difference between alligators and crocodiles. We also share some fun trivia on which species is bigger, faster and stronger.

Differences Between Alligators And Crocodiles

Alligator vs Crocodile
Alligator (top) and Crocodile (bottom)

When trying to compare an alligator vs crocodile, your location is the first thing you should think about.

If you are in the United States, you will not see a crocodile unless you are at the southern tip of Florida. Any other type of crocodilian in any other state is certainly an alligator. American gators can be found anywhere from east Texas to North Carolina.

You can also take a look at the environment. Crocodiles are able to swim in open streams due to their ability to regulate salt. Most alligators tend to stay closer to the shore, remaining in swamp lands and lakes.

Next you will want to take a good look at their body color. If it is light green, brown, or light grey, you have probably found a Crocodile. In the United States most crocodiles are almost always slate grey. If it has dark green or black scales, you have likely got a gator. The American alligator’s darker colors allow it to blend in better with the mud.

Now you should consider the size.

Crocodiles are on average three feet longer than alligators. In the United States, this is no exception. The American croc can reach a length of about 17 feet, while the maximum length for an American alligator is 13 to 14 feet.

Finally, you should try and look at the shape of the snout and the jaw. If you can get a good look, this is the easiest way to tell the two apart. Of course, you do not want to get too close to one! But even from a distance, the shape of the snout will tell you if you have got a gator or a croc.

Crocodiles always have a triangular snout in the shape of the letter V. This shape is the same no matter the species. Alligators have a rounded snout in the shape of a U. It is much wider and broader than a crocodile’s

If you do get a look at the teeth, you will notice that a crocodile has five visible bottom teeth. An alligator will only show the teeth on top.

Alligator Crocodile
Size 14 feet 17 feet
Weight 500 to 1000 pounds 800 to 1000+ pounds
Color Dark Green or Black Light Green, Brown or Light Grey
Snout Rounded U shape Triangular V shape
Teeth Only shows top teeth Five visible bottom teeth
Sates Most southeast states (i.e. from east Texas to North Carolina) Florida

In the United States, both alligators and crocodiles tend to be shy and timid. This is similar to most reptile and lizard species. However, you should always keep a safe distance from them.

1. Alligators Are Dark Green Or Black

Alligator
American Alligator

Color is one of the easiest ways to tell the difference between crocodiles and alligators.

Most crocodiles come in shades of green, grey, brown, or black. They usually have a mottled or speckled pattern which helps them to blend in with algae and substrate.

American crocodiles are normally slate grey and have a white to yellow underside. This dark and light coloration is called countershading. It allows them to blend into the water while on the hunt.

Other species of crocodiles come in different shades, depending on the colors of their environments.

For example, the saltwater crocodile is the best example of the typical ‘green crocodile.’ Its dark green scales help it blend in with algae. The Nile crocodile comes in deep green and brown speckles that match the substrate of the Nile River.

In contrast, Alligators usually come in dark green to black.

The American alligator is a shiny dark green that can look almost black in certain lights. It is much darker color than a crocodile.

Just like a crocodile, their colors will vary based upon their habitat.

Crocodiles tend to live in open water areas with much more algae. Because of this they are usually going to come in greener shades to match. Alligators tend to stay near the banks of rivers and lakes. Their colors are designed to blend in with the mud and the substrate.

2. Crocodiles Are Bigger Than Alligators

Nile crocodile
Nile crocodile

Most crocodiles are larger than alligators. The saltwater crocodile is the largest and can reach lengths of up to 23 feet.

The American crocodile reaches a maximum length of 20 feet, but is usually between 15 and 17 feet. It weighs anywhere from 800 to just over 1000 pounds.

American alligators are smaller than crocodiles.

Male alligators reach an average length of between 12 and 13 feet and can weigh up to 1000 pounds. Females are between 8 and 10 feet and weigh in at 500 to 700 pounds.

An American croc is larger than an alligator by about 4 to 6 feet on average. However, it can be difficult to eyeball the size of an animal when seen from a distance. For this reason size is one of the hardest ways to identify each species.

3. Crocodiles Have V-Shaped Snouts

Alligator vs Crocodile

When you first see a crocodilian, the snout should be the first thing you look at if you want to know what it is. Snout and jaw shape are the easiest way to tell the difference between alligators and crocodiles.

Alligators have large, broad snouts that are shaped like the letter U.

Every crocodile species have pointed, V-shaped snouts.

A crocodile’s snout may be very wide or very narrow, but it will always have the same pointed shape. Their jaws also close from the top-down, rather than from the bottom-up.

This overbite and underbite means a croc’s jaw exposes both its top and bottom teeth, in a sort of ‘jagged’ formation. If you look closely, you will see five of its bottom teeth.

Unlike a crocodile, the alligator’s jaw closes downwards and you can only see their top teeth. Notches in their bottom jaw hide the bottom teeth when their mouth is shut.

Of course, you do not want to get close enough to a croc or a gator to be able to see their teeth!

4. Crocs Have A More Powerful Bite!

Crocodile teeth

Crocodiles’ teeth are sharp and pointed because they are designed for tearing. Crocs have an incredible bite strength of about 3700 psi.

The alligator’s jaw is meant for crushing prey, instead of tearing. This is why their teeth are cone shaped rather than pointed. Their bite strength is about 2500 psi.

5. Alligators Have Tiny Black Spots

American alligator

Crocodiles and alligators both have dome pressure receptors on their skin. These receptors allow them to regulate water pressure when swimming and detect ripples in the water.

Alligator’s dome pressure receptors are visible as tiny black spots near their jaw.

The dome pressure receptors of a crocodile are translucent and scattered all over their body. This is one of the reasons they swim better in open water when compared to gators.

Crocodiles also have salt glands on their tongues, which allow them to osmoregulate in high salinity areas. Alligators do not have any salt glands.

6. Gators Can Live In Colder States

Most species of crocodile live in marshes and wetlands alongside rivers and lakes. Sometimes they may venture out into fast-moving streams, rivers and channels because they are able to live in salty waters.

Alligators normally live closer to the shore. Their natural habitat is mostly swamp lands, lakes and low flow areas of rivers. They are not able to live in saline waters.

Temperature is the reason why the American alligator lives in more states than a crocodile.

Both species are cold blooded, but crocodiles need a higher temperature to survive. You can find them in temperature ranges from 85 to 93°F. Alligators can survive in temperatures as low as 79°F before becoming dormant.

Alligators are more resistant to lower temperatures; they are able to live in colder areas.

The American alligator’s northernmost range reaches North Carolina vs. the American crocodile’s northernmost range of the southern tip of Florida.

If you are in the United States and not in south Florida, it is probably an alligator.

7. Crocodiles Are Slightly Older Than Alligators

Crocodiles can be traced back from around 70 million years ago to the late Cretaceous period. But, their ancestry goes back even farther than that. The animals that would later become crocodiles can be traced back to the Jurassic period. These aquatic crocodiles are known as ‘Thalattosuchia’ and lived over 200 million years ago.

The first land Crocodile is considered to be the Sarcosuchus. It appeared in fossil records about 110 million years ago and was over 40 feet long.

Alligators as we know them today can also be traced back to the late Cretaceous period, but their ancestors are not as old as Crocodile’s ancestors. Early alligators include Deinosuchus and Mourasuchus. These species are both from the late Cretaceous period and not the Jurassic period.

If we go by fossil records, Crocodiles are slightly older than alligators.

8. There Are Fewer Alligator Species

Both crocodiles and alligators both belong to the order Crocodilia. This order also includes caimans and gharials. Alligators and crocodiles belong to the same order, but they do not belong to the same family.

Crocodiles belong to the family Crocodylidae, which includes 13 different species. These species can be found in the United States, Australia, India, Africa and Southeast Asia. Interestingly the red eyed crocodile is a species of skink and not croc.

Alligators belong to the family Alligatoridae. This family includes two species of alligators and five species of caimans.

You can find two species of crocodilians in the United States:

  1. American alligator (Alligator mississipiensis)
  2. American crocodile (Crocodylus acutus)

9. Crocodiles Are More Aggressive

Saltwater crocodile
Crocodiles should never be approached or disturbed.

Larger crocodiles such as the Nile and Saltie are known for their attacks on humans. Crocs are opportunistic predators that will go after anything that moves. A hungry one will not hesitate to go after a human that gets too close.

There are several hundred reported crocodile attacks on humans every year. This is more than the number of annual shark attacks. Most of these attacks happen in Australia where the Saltie lives, but the Nile crocodile is very dangerous too.

American crocs are shy compared to other species. They are more likely to shy away from humans unless they are provoked.

Alligators make up less than six percent of all reported crocodilian attacks. An alligator is often more afraid of you than you are of it. They will only attack when disturbed or when it is protecting its eggs or young.

Alligators and Crocodiles Frequently Asked Questions

American crocodile

Crocodile vs Alligator Fight

One of the most common questions is who would win in a fight between an alligator and a crocodile? In a hypothetical fight, the crocodile would be the most likely winner. It has a bite strength over 3500 psi and is likely to attack, even when unprovoked.

In comparison, the American alligator’s bite strength is only about 2,900 psi and they are also smaller in both size and weight.

Can Alligators Live with Crocodiles?

The southernmost tip of Florida is the only place in the United States where you can see crocodiles and alligators together. But, even in South Miami, they do not live in the same habitat.

Alligators live in the swamps and marshes along the banks of lakes and rivers.

Crocodiles venture out into open water, fast-moving streams, rivers and channels where the river meets the sea.

Is An Alligator Faster Than A Crocodile?

Alligators and crocodiles may look lazy while they are basking in the sun, but both can easily outrun a human. Speed is one area where gators have an advantage. Alligators are much faster.

On land, an alligator can hit speeds of up to 30 miles per hour! Crocodiles can only reach about 20 miles per hour over a very short distance.

In the water, an alligator’s speed is slowed to about 25 miles per hour. A croc’s speed is also slowed to about 18 miles per hour.

Summary

You should now be able to tell the difference between an alligator vs crocodile. The main thing to remember is that alligators and crocodiles are different species. They can be identified by their jaw shape, size and color.

Alligators are dark green or black, have u-shaped snouts, tiny black spots and are smaller than crocs.

Crocodiles are bigger, have v-shaped snouts and are more aggressive. They also have visible bottom teeth and are light green, brown or light grey.

Both gators and crocs in the United States are more afraid of you than you are of them.

In the state of Florida, alligators and crocodiles are just another part of the native wildlife. The best thing you can do is to show them respect and always keep a safe distance.

About Johnathan David 149 Articles
Johnathan leads the Everything Reptiles’ editorial team as our Editor in Chief. He has been a reptile hobbyist since childhood and after years in herpetoculture he has cared for many Geckos and Frogs.

4 Comments

  1. I was wondering what the biological relationship was between the two species. Do they have a common ancestor or is it one of those ‘convergent evolution’ things?
    I didn’t know before reading this that there were any crocodiles in the US.

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