It is one of the most-searched questions in the animal world: which is the biggest snake, the Green Anaconda or the reticulated python? The answer hinges on what you mean by big. One wins on weight, the other on length. Here is the clear, point-by-point comparison. For deeper detail on one of the two, see our Green Anaconda species guide.
The short answer
The Green Anaconda (Eunectes murinus) is the heaviest snake on Earth. The reticulated python (Malayopython reticulatus) is the longest. Both are non-venomous constrictors, but they are built very differently.
Weight and build
The anaconda is the bulk champion. Its body is thick, heavily muscled and broad, and large females approach 100 kg. A roughly 5-metre anaconda can weigh about the same as a reticulated python well over 7 metres long, because the python is far more slender for its length.
Length
The reticulated python takes the length crown. Today's largest credibly measured individuals reach the 7 to 8 metre range, edging past the anaconda, which rarely exceeds about 6.25 metres in verified measurements.
Where they live
- Green Anaconda: slow rivers, swamps and flooded grasslands of tropical South America.
- Reticulated python: tropical forests and wetlands of Southeast Asia, including Indonesia and the Philippines.
Hunting and lifestyle
The anaconda is strongly semi-aquatic, lying submerged with eyes and nostrils on top of its head to ambush prey at the water's edge. The reticulated python is more at home on land and in trees. Both kill by constriction and swallow prey whole.
Other key differences
- Reproduction: the Green Anaconda gives live birth in water, while reticulated pythons lay eggs.
- Colour: the anaconda is olive-green with black blotches; the python wears an intricate diamond-like net pattern.
- Conservation note: in 2024 the Green Anaconda was split, with northern populations named Eunectes akayima.
So which is the biggest?
If biggest means heaviest and bulkiest, the Green Anaconda wins. If it means longest, the reticulated python does. Both face pressure from habitat loss and the skin and pet trade, and keeping their wetlands and forests intact is what secures their future. That habitat-first work is something a modest gift can quietly support.
Read the full Green Anaconda wildlife guide for the facts, IUCN status and conservation context — or donate to WARN to help fund the local partners protecting this species.
