Biggest Snakes in the World by Length and by Weight

"The question of size is a tricky one," says Jesus Rivas, a herpetologist and professor of biology at New Mexico Highlands University. Imagine if someone asked you, "What's the largest land mammal?" According to Rivas, you would "answer before hesitation" that it's the African savanna elephant.

"Nobody would start bellyaching as to how much taller giraffes are. Simply because when we mean size, mass is the determining factor," he says. "That is why I simply say anacondas are the largest snakes in the world, period."

Exact measurements are hard to pin down. Green anacondas — and reticulated pythons — are incredibly strong beasts. Not only that, but a massive snake doesn't always react well to handling.

With all that in mind, we've divided our lists into "longest" and "heaviest," though you'll notice a few species that find their way into the top ranks of both categories.

From nose to tail, these are the six longest snakes in the world.

1. Reticulated Python (up to 32 feet/9.8 meters)

The reticulated python — or "retic" — is a marvel of nature, embodying the extremes of reptilian growth. Native to the lush rainforests of South and Southeast Asia, Malayopython reticulatus is recognized for its striking pattern, a complex mosaic of diamond shapes interspersed with intricate lines and vibrant colors.

Adults can achieve astonishing lengths: On average, adult retics typically range from 10 to 20 feet in length.

These constrictors, while nonvenomous, are formidable predators, relying on their immense strength to subdue prey, which includes a variety of mammals and the occasional bird.

The longest snake in the world gets big enough to swallow pigs, deer — and yes, the occasional human. This comes as no surprise to Richard Shine, a biologist at Australia's Macquarie University.

In an email interview, Shine says he "encountered one individual female that was almost 23 feet [7 meters] long" while conducting research in Sumatra. "[Females] grow longer than males in both the reticulated python and the anaconda, so the biggest snake in the world (wherever she is) is doubtless a female," he notes.

Gulp!

In a 2005 report, another plus-sized retic — from the island of Borneo — was measured at 22 feet, 10 inches (6.95 meters) long. Fun fact about that snake: It ate a bear.

Somehow, a wild, 50-pound (23-kilogram) sun bear who'd been wearing a radio collar caught the reptile's attention. The retic swallowed it whole, collar and all. Researchers later tracked the python down for examination.

2. Green Anaconda (up to 30 feet/9.1 meters)

Found in the Amazon Basin, these muscular marvels are ambush predators, which means they wait — sometimes completely submerged in water — for their prey to wander within striking distance. They don't have venom, so they use their sheer strength to constrict and overpower their victims.

3. Scrub Python (up to 27 feet/8.2 meters)

Also known as amethystine pythons, these are the longest snakes in Australia. With a slender body and a strong bite, scrub pythons are skilled hunters, preying on everything from birds to marsupials.

Unlike anacondas, scrubs don't rely on water; they're all about the trees and rocky outcrops. They're like the rock climbers of the snake world, showing us just how adaptable legless reptiles can be.

4. African Rock Python (up to 24 feet/7.3 meters)

These powerful snakes are known for their striking patterns and aggressive nature. The African rock python is often found in savannas, grasslands and forests, where it hunts mammals as large as antelope and crocodiles.

5. Indian Python (up to 20 feet/6.1 meters)

Known for its calm demeanor, this serpent often pops up found in grasslands, swamps and forests across South Asia. Indian pythons are skilled swimmers, just like the anaconda, and they enjoy a good soak when they can find water.

6. King Cobra (up to 18 feet/5.5 meters)

The king cobra (Ophiophagus hannah) demands respect as the world's longest venomous snake. With lengths up to 19 feet (5.85 meters), it is a true giant among its kind.

This snake, native to South and Southeast Asia's dense forests, is distinguished by its chevron-patterned skin and exceptional behavior; it is notably the only snake that constructs nests for its eggs, displaying a fierce maternal protection.

The diet of the king cobra is as remarkable as its nesting habits — it preys on other snakes, even large pythons, earning its moniker "snake-eater." Although its venom is not the most toxic, in a single bite, the king cobra can unleash enough neurotoxins to bring down an elephant or multiple humans.

Beyond its ecological role, the king has also coiled itself into pop culture. It has inspired characters like the hypnotic Kaa in Rudyard Kipling's "The Jungle Book," and its fearsome image is central to the "Cobra Kai" dojo in the "Karate Kid" franchise, symbolizing strength and resilience.

These are the snakes that tip the scale the most — literally.

1. Green Anaconda (up to 550 lbs/249 kg)

Rivas has been studying green anacondas in their natural habitat for three decades and counting.

"The largest [green anaconda] I have caught was a bit more than 220 pounds [100 kilograms]," Rivas tells us via email. "There are figures of 500 pounds [227 kilograms] that I do not doubt," he says.

Indeed, the green anaconda (Eunectes murinus) is the world's heaviest snake species. Native to South America, it thrives in aquatic environments like swamps and slow-moving rivers.

Here's the rub: Green anacondas are more heavily built animals than retics.

Due to their hulking proportions, experts agree that the South American snakes can get much, much heavier than even the largest of pythons. Yet, when it comes to body length, reticulated pythons might actually have a slight edge.

Rivas says there are records that suggest that, when comparing the two snakes, retics grow longer:

2. Burmese Python (up to 403 lbs/183 kg)

Despite their size, Burmese pythons (Python bivittatus) are excellent swimmers and can stay submerged for up to half an hour before surfacing for air. They are also known for their distinctive color pattern, featuring brown blotches bordered in black down the length of their bodies.

Unlike some of their other slithering pals, Burmese pythons are both predators and prey. They are apex predators in their habitat, but their young are often hunted by larger animals.

These gentle giants, while nonvenomous, are constrictors, subduing their prey with immense strength before consumption.

3. Reticulated Python (up to 350 lbs/159 kg)

It should come as no surprise that the world's longest snake is also one of the heaviest. Native to Southeast Asia, it's got a muscular build and a dazzling pattern across its scales, which helps it blend into forests and grasslands.

4. African Rock Python (up to 200 lbs/91kg)

African rock pythons (Python sebae) hold the title as Africa's largest snake, with the capacity to reach lengths of up to 4.8 meters (15.7 feet). This formidable constrictor inhabits a wide range of environments across sub-Saharan Africa, from savannas to rainforests, showcasing its adaptability.

Its mottled, earthy coloration not only provides excellent camouflage amongst the African wilderness but also underscores its raw, natural beauty.

The rock python exhibits remarkable maternal instincts; females aggressively guard their eggs until they hatch, which is unusual among snakes.

These pythons have a voracious appetite, able to prey on animals as large as antelopes. And due to their size and strength, they have few natural predators once they reach adulthood.

5. Indian Python (up to 200 lbs/91 kg)

Tying the African rock python for the No. 4 spot, an Indian python can easily outweigh a small child. With a solid frame to support their substantial girth, these snakes aren't exactly carry-on-sized. Females are often larger than males, which is typical for pythons.

6. Scrub Python (up to 77 lbs/35 kg)

While the Australian scrub python comes in at less than half the weight of the previous entry on this list, it's not exactly a lightweight. This particular species is nocturnal, so its vertical pupils help it adapt to low light levels as it uses heat-sensing pits in its mouth to hunt for prey at night.

Oh, you thought we were done? No no, there are a couple of even bigger snake species that put the longest reticulated python of today to shame.

1. Titanoboa

Some 58 million years ago, a gargantuan snake patrolled the rivers of Colombia. Named Titanoboa cerrejonensis, the animal swims those waters no more.

Experts aren't sure why the reptile died out. Maybe climate change did this species in — or perhaps it just couldn't compete with the big, carnivorous mammals who later arrived on the scene. What we do know is that Titanoboa was absolutely, positively gigantic.

Although nobody's ever found a complete skeleton, paleontologists have an assortment of Titanoboa fossils to go on, including ribs, backbones and pieces of skull. They paint a striking image of the long-extinct creature.

Judging by the available remains, it seems Titanoboa could have probably weighed over 1.25 tons (over 1.13 metric tons) and surpassed 42 feet (12.8 meters) in length. That would make it the largest known snake of all time.

2. Gigantophis garstini

This prehistoric snake from about 40 million years ago roamed what's now Northern Africa and is estimated to have reached an epic length of 36 feet (11 meters). During the Eocene epoch, it likely ruled its environment, possibly preying on ancient crocodiles and other large reptiles.

Fossil remains found in Egypt's Fayum region revealed just how gigantic this snake was. Gigantophis garsitini belonged to the now-extinct Madtsoiidae family, and scientists believe it had a broad distribution, hinting at an era when giant reptiles were still top predators on land and in water.

We updated this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.