When it comes to sheer mass, no snake rivals the green anaconda of South America. While the reticulated python can grow longer, the anaconda's thick, muscular body gives it a decisive weight advantage. This list ranks the ten heaviest snake species by their maximum reliably recorded body weight.
Weight varies enormously within a species depending on age, sex, and access to prey. The figures below represent the maximum documented weights for each species, drawn from scientific literature, zoo records, and expert field guides.
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Maximum weight (kg)
Maximum weight (kg)
Green Anaconda
250 kg
Burmese Python
183 kg
Reticulated Python
158 kg
African Rock Python
91 kg
Yellow Anaconda
55 kg
Indian Python
52 kg
Amethystine Python
50 kg
Boa Constrictor
45 kg
Dark-spotted Anaconda
40 kg
Olive Python
35 kg
The ranking
1
Green Anaconda
The green anaconda (Eunectes murinus) is the heaviest snake in the world, with reliably documented specimens exceeding 250 kg. Found in the swamps and rivers of the Amazon and Orinoco basins, females are significantly larger than males. The largest verified specimen measured 5.21 metres and weighed 227 kg, though unconfirmed reports reach 5.5 metres and 250 kg.
Maximum weight: 250 kg (550 lb)Scientific name: Eunectes murinusAverage length: 4–5 mRange: South America (Amazon, Orinoco)Diet: Caimans, capybaras, deer, fish
2
Burmese Python
The Burmese python (Python bivittatus) is one of the largest snake species by weight, with documented specimens exceeding 180 kg. Native to Southeast Asia, it has also become an invasive apex predator in the Florida Everglades, where large females can reach 140 kg. The heaviest reliably recorded captive specimen weighed 183 kg.
Maximum weight: 183 kg (403 lb)Scientific name: Python bivittatusAverage length: 4–6 mRange: Southeast Asia; invasive in FloridaDiet: Mammals, birds, occasionally alligators
3
Reticulated Python
The reticulated python (Malayopython reticulatus) is the longest snake species in the world, with verified specimens exceeding 7 metres, but it is more slender than the anaconda. The heaviest reliably documented specimen weighed approximately 158 kg. Its distinctive geometric pattern gives it its name.
Maximum weight: 158 kg (348 lb)Scientific name: Malayopython reticulatusAverage length: 6–7 mRange: Southeast Asia, Philippines, IndonesiaDiet: Primates, deer, pigs, birds
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4
African Rock Python
The African rock python (Python sebae) is Africa's largest snake species. Large females can reach 90 kg and 5 metres in length. It is found across sub-Saharan Africa in savannas, grasslands, and near water sources. It is known for its aggressive temperament and powerful constriction.
Maximum weight: 91 kg (200 lb)Scientific name: Python sebaeAverage length: 4–5 mRange: Sub-Saharan AfricaDiet: Antelopes, monkeys, crocodiles
5
Yellow Anaconda
The yellow anaconda (Eunectes notaeus) is a smaller relative of the green anaconda, found in the Paraguay River basin. It reaches maximum weights of around 55 kg, making it the fifth-heaviest snake species. Despite its smaller size, it is a powerful constrictor of capybaras and caimans.
Maximum weight: 55 kg (121 lb)Scientific name: Eunectes notaeusAverage length: 3–4 mRange: Paraguay, Argentina, Bolivia, BrazilDiet: Birds, rodents, capybaras, fish
6
Indian Python
The Indian python (Python molurus) is a large, heavy-bodied constrictor found across the Indian subcontinent. It is slightly smaller than its Burmese cousin, with maximum weights reaching approximately 52 kg. It was once considered the same species as the Burmese python but is now classified separately.
Maximum weight: 52 kg (115 lb)Scientific name: Python molurusAverage length: 3–4 mRange: Indian subcontinentDiet: Mammals, birds, amphibians
7
Amethystine Python
The amethystine python (Simalia amethistina) is Australia's largest snake species, found in Queensland, Papua New Guinea, and Indonesia. Large specimens can exceed 5 metres and reach 50 kg. It is named for the iridescent amethyst sheen on its scales.
Maximum weight: 50 kg (110 lb)Scientific name: Simalia amethistinaAverage length: 4–5 mRange: Australia, Papua New Guinea, IndonesiaDiet: Wallabies, possums, birds
8
Boa Constrictor
The boa constrictor (Boa constrictor) is a medium-to-large snake found across Central and South America. While most specimens weigh 10–20 kg, exceptionally large females can reach 45 kg. It is one of the most well-known snake species and is commonly kept in captivity.
Maximum weight: 45 kg (99 lb)Scientific name: Boa constrictorAverage length: 2–3 mRange: Central and South AmericaDiet: Rodents, monkeys, birds, iguanas
9
Dark-spotted Anaconda
The dark-spotted anaconda (Eunectes deschauenseei) is a rare anaconda species found in northeastern Brazil and French Guiana. It reaches approximately 40 kg and 3 metres in length, making it the smallest of the four anaconda species but still one of the heaviest snakes in the world.
Maximum weight: 40 kg (88 lb)Scientific name: Eunectes deschauenseeiAverage length: 2.5–3 mRange: Northeastern Brazil, French GuianaDiet: Fish, birds, small mammals
10
Olive Python
The olive python (Liasis olivaceus) is Australia's second-largest snake species, found in the northern and western regions of the continent. Large specimens reach 35 kg and 4 metres in length. It is named for its uniform olive-green colouration.
Maximum weight: 35 kg (77 lb)Scientific name: Liasis olivaceusAverage length: 3–4 mRange: Northern and Western AustraliaDiet: Wallabies, bandicoots, birds
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Full comparison
#
Name
Maximum weight
Scientific name
Average length
Range
Diet
1
Green Anaconda
250 kg (550 lb)
Eunectes murinus
4–5 m
South America (Amazon, Orinoco)
Caimans, capybaras, deer, fish
2
Burmese Python
183 kg (403 lb)
Python bivittatus
4–6 m
Southeast Asia; invasive in Florida
Mammals, birds, occasionally alligators
3
Reticulated Python
158 kg (348 lb)
Malayopython reticulatus
6–7 m
Southeast Asia, Philippines, Indonesia
Primates, deer, pigs, birds
4
African Rock Python
91 kg (200 lb)
Python sebae
4–5 m
Sub-Saharan Africa
Antelopes, monkeys, crocodiles
5
Yellow Anaconda
55 kg (121 lb)
Eunectes notaeus
3–4 m
Paraguay, Argentina, Bolivia, Brazil
Birds, rodents, capybaras, fish
6
Indian Python
52 kg (115 lb)
Python molurus
3–4 m
Indian subcontinent
Mammals, birds, amphibians
7
Amethystine Python
50 kg (110 lb)
Simalia amethistina
4–5 m
Australia, Papua New Guinea, Indonesia
Wallabies, possums, birds
8
Boa Constrictor
45 kg (99 lb)
Boa constrictor
2–3 m
Central and South America
Rodents, monkeys, birds, iguanas
9
Dark-spotted Anaconda
40 kg (88 lb)
Eunectes deschauenseei
2.5–3 m
Northeastern Brazil, French Guiana
Fish, birds, small mammals
10
Olive Python
35 kg (77 lb)
Liasis olivaceus
3–4 m
Northern and Western Australia
Wallabies, bandicoots, birds
How we ranked this
Snakes are ranked by their maximum reliably recorded body weight in kilograms. Only species with multiple documented records are included; anecdotal or unverified claims are excluded. Where multiple subspecies exist, the heaviest subspecies is listed. Rank 1 is the heaviest species. Data is drawn from scientific literature, including the Guinness World Records, peer-reviewed herpetology journals, and expert field guides such as the Handbook of Snakes and Reptile Database.
FAQ
What is the heaviest snake in the world?
The green anaconda (Eunectes murinus) is the heaviest snake species, with reliably documented specimens exceeding 250 kg. It is native to the Amazon and Orinoco river basins of South America.
Which is longer — the anaconda or the reticulated python?
The reticulated python is the longest snake species, with verified specimens exceeding 7 metres. However, the green anaconda is much heavier due to its thicker, more muscular body.
How do scientists weigh large snakes?
Large snakes are typically weighed using heavy-duty scale mats or industrial hanging scales. For wild specimens, biologists often use a combination of length and girth measurements with species-specific weight-estimation formulas.
Can a snake weigh more than 250 kg?
While unverified reports of green anacondas reaching 500 kg exist, no specimen over 250 kg has been scientifically documented and verified. The largest verified anaconda weighed 227 kg at 5.21 metres.