Alligators and crocodiles are distinct species within the ancient order Crocodilia. Despite their similar appearances, key differences exist between them. Understanding these distinctions helps clarify how to tell them apart and appreciate their unique characteristics.
Size Differences
Crocodiles generally grow larger than alligators, though significant overlap in size can occur. The American alligator, one of two alligator species, typically reaches 11.2 to 14.8 feet (3.4 to 4.5 meters) and weighs up to 1,100 pounds (500 kg). Females are smaller, usually 8.5 to 9.8 feet (2.6 to 3 meters). The largest American alligator on record was 14 feet 3.5 inches (4.36 meters) long, with the heaviest verified at 1,380 pounds (625.96 kg). The Chinese alligator, the other species, is considerably smaller, typically growing to 4 to 6 feet (1.2 to 2.4 meters) and weighing 50 to 85 pounds (22 to 38 kg).
Among crocodiles, the saltwater crocodile is the largest living reptile, with males commonly reaching 15 to 23 feet (4.6 to 7 meters) and weighing 1,000 to 2,645 pounds (450 to 1,200 kg). The longest verified saltwater crocodile measured 20.7 feet (6.32 meters) and weighed about 3,000 pounds (1,360 kg). Other large crocodile species include the Nile crocodile, which can grow up to 20 feet (6 meters) and weigh around 1,600 pounds (748 kg), and the American crocodile, sometimes reaching 10 to 20 feet (3 to 6.1 meters) and weighing 300 to 2,000 pounds (136 to 907 kg). While crocodiles tend to be larger, a very large alligator can sometimes exceed the size of a smaller crocodile species.
Distinctive Physical Characteristics
Beyond size, several physical traits allow for visual differentiation between alligators and crocodiles. A primary distinguishing feature is snout shape. Alligators possess a broader, U-shaped snout. In contrast, crocodiles typically have a narrower, more pointed V-shaped snout. This difference in snout morphology is often associated with their diets, with the broader alligator snout suited for crushing hard-shelled prey.
Another difference is how their teeth are visible when their mouths are closed. An alligator’s upper jaw is wider than its lower jaw, causing the upper teeth to overlap and hide most lower teeth. Conversely, crocodiles have upper and lower jaws of similar width, allowing both rows of teeth to interlock and remain visible, especially the fourth lower tooth, which protrudes noticeably. This gives crocodiles a “toothy grin.”
Alligators also have more teeth, around 80, compared to approximately 66 in crocodiles. Additionally, alligators typically have darker coloration, often gray or black, while crocodiles generally have lighter hues like olive, tan, green, or brown.
Habitat and Distribution
Alligators and crocodiles also differ in their preferred habitats and geographical distribution. Alligators primarily inhabit freshwater environments such as ponds, marshes, wetlands, rivers, lakes, and swamps. They are predominantly found in the southeastern United States, across states like Florida, Louisiana, Georgia, and Texas, and also in a small region of eastern China. Alligators have a limited tolerance for saltwater because they lack functional salt-excreting glands.
In contrast, crocodiles are more globally widespread, inhabiting tropical and subtropical regions across Africa, Asia, Australia, and the Americas. Many crocodile species can tolerate saltwater and brackish water environments, such as estuaries and coastal areas, due to their specialized salt glands. The American crocodile is an exception, found in coastal, brackish environments in southern Florida, Cuba, Mexico, and as far south as Peru. Southern Florida is the only place where both alligators and American crocodiles coexist in the wild.