The most venomous snakes in the world

How the ranking works

Venom toxicity is compared with the LD50 test: groups of mice are injected with measured doses, and the LD50 is the dose, in milligrams of venom per kilogram of mouse, that kills half of them¹. The lower the number, the more toxic the venom. The Australian figures in this list come from the 1979 study by Broad, Sutherland and Coulter, which tested dangerous Australian snakes and several from other continents under one method and is still the usual source for them^1,2. The Australian Museum calls the inland taipan’s venom “the most toxic of all snake venoms in LD50 tests on mice”³.

The numbers are less precise than they look. Results change with the injection route (under the skin, into the abdomen or into a vein), with the liquid the venom is dissolved in, and with the snakes the venom came from^1,2. The inland taipan’s LD50 was 0.025 mg/kg in saline in 1979 and 0.0225 mg/kg in a 2014 test². Published intravenous values for the many-banded krait range from 0.014 to 0.071 mg/kg⁶, and the common krait’s venom was up to five times more potent in some Indian states than in others, from 0.045 to 0.251 mg/kg⁷. Mice are not people, either. So treat the list as a rough order, not a league table, and treat differences of a few hundredths of a milligram as noise. Where a figure was measured by a different route, the list says so.

What LD50 does not tell you

A toxic venom does not make a snake dangerous to people. The inland taipan lives in remote parts of central Australia, is shy, and has bitten only a handful of people, all of whom survived³. Dubois’ sea snake has the most toxic venom of any sea snake, but the far less toxic beaked sea snake causes more deaths, because it lives in estuaries and gets tangled in fishing nets^4,5. The eastern brown snake, lower on the list than the inland taipan, caused 17 of the 23 snakebite deaths recorded by the Australian Snakebite Project between 2005 and 2015, and the tiger snake four¹⁶.

What matters in practice is how much venom a snake injects, how long its fangs are, how often it meets people, how its venom damages the body and whether antivenom is available^11,12. The black mamba’s venom is less toxic in mice than that of any Australian elapid on this list, at 0.38 mg/kg by intraperitoneal injection, yet it injects a large quantity of it⁹. The puff adder and the West African carpet viper have venoms that are 50–70 times less toxic than the inland taipan’s by the same kind of test, and they are among the most important causes of snakebite death in Africa^10,15,17.

The snakes that kill the most people

The World Health Organization estimates that about 5.4 million people are bitten by snakes each year, 1.8 to 2.7 million of them are envenomed, and 81,410 to 137,880 die, with about three times as many left with amputations or other permanent disabilities¹¹. A 2008 modelling study put the toll at 421,000 to 1,841,000 envenomings and 20,000 to 94,000 deaths a year, with the heaviest burden in South Asia, South-East Asia and sub-Saharan Africa¹². None of the top five snakes on the LD50 list appears among the main killers.

India carries the largest share. A nationally representative mortality study estimated 1.2 million snakebite deaths there between 2000 and 2019, about 58,000 a year, 94% of them in rural areas and nearly 70% in eight high-burden states¹³. Most are caused by the “big four”: Russell’s viper, the saw-scaled viper, the Indian cobra and the common krait, which are the species India’s antivenom is made against¹⁴. Among the studies that identified the snake, Russell’s viper accounted for 43% of cases¹³. Kraits bite people asleep on the floor at night, and saw-scaled vipers are stepped on in the dark¹³.

In Africa, the WHO’s regional guidelines name the West African carpet viper and the puff adder among the species responsible for most serious bites¹⁵. In Nigeria the carpet viper has been reported to cause about 90% of snakebites and 60% of snakebite deaths¹⁷. In Australia, the eastern brown snake is the main killer¹⁶. The snakes that top the LD50 table, the inland taipan and the coastal taipan, hardly feature in these counts^3,16.

What to do with this list

Use it to understand venom, not to judge which snakes are safe to approach. Every snake on this page can kill, and so can many that are not on it. Keep your distance from any snake you cannot identify, never try to catch or kill one, and if someone is bitten, keep them still and get them to hospital: the WHO’s first-aid advice is to remove rings and tight items, splint the limb, avoid tourniquets, cutting and suction, and reach a health facility as soon as possible^11,14. Our country first-aid pages for India, Australia, Bangladesh and the United States give the emergency numbers and the steps that apply there^14,16.