Ask which snake is the largest and the honest answer depends on whether you mean longest or heaviest. By weight, there is no contest: the Green Anaconda (Eunectes murinus) is the heaviest snake on Earth. This explainer breaks down the real numbers and separates record from rumour. For the canonical profile, visit our Green Anaconda species guide.
How heavy is a Green Anaconda?
Fully grown females typically weigh tens of kilograms, and verified large individuals approach 100 kg. Exceptionally bulky specimens, almost always pregnant females or snakes that have just swallowed a big meal, have been reported well beyond that. What sets the anaconda apart is girth: a relatively short anaconda can outweigh a much longer python because its body is so thick and muscular.
How long is a Green Anaconda?
Large females commonly exceed 5 metres, while males average around 3 metres. Credible measurements rarely pass about 6.25 metres; historical claims of snakes far longer have never held up to verification and should be treated with caution.
Why are females so much bigger?
Green Anacondas display reverse sexual size dimorphism, meaning females dwarf males. A larger female can carry more and bigger young, and during courtship several modest-sized males may coil around one giant female in a breeding ball.
How does that compare to other big snakes?
- Heaviest: Green Anaconda, by a wide margin in bulk and girth.
- Longest: the reticulated python of Southeast Asia edges ahead in length.
- Bottom line: a roughly 5-metre anaconda can weigh about as much as a python well over 7 metres long.
Why size makes them vulnerable
That same impressive size drives demand for the snake's large, patterned skin and fuels the exotic pet trade, which is why all anacondas are listed on CITES Appendix II. Protecting the slow wetlands they depend on is the surest way to keep giants like these in the wild, and supporting that quiet habitat protection work helps the local teams doing it.
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.
