The ten snakes with the most potent venom on Earth, ranked by subcutaneous LD50 — from the inland taipan's record-breaking neurotoxin to the tiger snake's complex cocktail.
Snake venom potency is measured by LD50 (Lethal Dose, 50%) — the amount of venom required to kill 50% of a test population, expressed in milligrams per kilogram of body weight. The lower the LD50 value, the more potent the venom. Australia is home to the majority of the world's most venomous snakes, a consequence of the continent's unique evolutionary history and isolation.
This list ranks the ten deadliest snakes by their subcutaneous LD50 value in mice, the standard metric for comparing venom potency across species. Rankings reflect the inherent toxicity of each snake's venom, not the amount delivered per bite, the snake's aggression level, or the number of human fatalities. The difference between the top-ranked snakes is small — the inland taipan and the eastern brown snake are separated by a fraction of a milligram.
Ad · leaderboard
LD50 (mg/kg, lower = more potent)
LD50 (mg/kg, lower = more potent)
Inland Taipan (Oxyuranus microlepidotus)
0.0 mg/kg SC LD50
Eastern Brown Snake (Pseudonaja textilis)
0.0 mg/kg SC LD50
Coastal Taipan (Oxyuranus scutellatus)
0.1 mg/kg SC LD50
Dubois' Sea Snake (Aipysurus duboisii)
0.1 mg/kg SC LD50
Common Death Adder (Acanthophis antarcticus)
0.1 mg/kg SC LD50
Black Mamba (Dendroaspis polylepis)
0.3 mg/kg SC LD50
Tiger Snake (Notechis scutatus)
0.3 mg/kg SC LD50
Beaded Sea Snake (Hydrophis schistosus)
0.3 mg/kg SC LD50
Many-Banded Krait (Bungarus multicinctus)
0.3 mg/kg SC LD50
King Cobra (Ophiophagus hannah)
0.4 mg/kg SC LD50
The ranking
1
Inland Taipan (Oxyuranus microlepidotus)
The inland taipan, also known as the fierce snake or western taipan, holds the record for the most potent venom of any snake, with a subcutaneous LD50 of 0.025 mg/kg. A single adult carries enough venom to kill approximately 100 adult humans. Despite its fearsome reputation, the inland taipan is a shy and reclusive species found in remote semi-arid regions of Queensland and South Australia. Its venom is a complex mixture of neurotoxins (including taipoxin), hemotoxins, and myotoxins. There have been no documented fatalities since the introduction of specific antivenom.
Scientific name: Oxyuranus microlepidotusFamily: ElapidaeRange: Central-east Australia (semi-arid regions)Average length: 5.9–8.2 ft (1.8–2.5 m)Venom yield per bite: 44–110 mg (dry weight)
2
Eastern Brown Snake (Pseudonaja textilis)
The eastern brown snake has the second-most potent venom of any snake, with an LD50 of 0.0365 mg/kg SC. It is responsible for more snakebite fatalities in Australia than any other species — approximately 60% of all snakebite deaths — due to its abundance near human settlements and aggressive defense of territory. Its venom is a powerful procoagulant that causes rapid, catastrophic bleeding by depleting the body's clotting factors. Eastern brown snakes can grow up to 6.6 feet (2 meters) and are found along the eastern coast of Australia from Queensland to South Australia.
Scientific name: Pseudonaja textilisFamily: ElapidaeRange: Eastern and southern Australia, southern Papua New GuineaAverage length: 4.9–6.6 ft (1.5–2.0 m)Venom yield per bite: 4–13 mg (dry weight)
3
Coastal Taipan (Oxyuranus scutellatus)
The coastal taipan ranks third with an LD50 of 0.064 mg/kg SC. It is the largest Australian elapid, growing up to 9.8 feet (3 meters), and delivers a far larger volume of venom per bite than the inland taipan — up to 120 mg dry weight. Its venom contains taipoxin, one of the most potent neurotoxins known, which causes progressive paralysis. Found in coastal regions of northern and eastern Australia and southern Papua New Guinea, the coastal taipan is considered more dangerous than the inland taipan due to its larger size, higher venom yield, and more aggressive temperament.
Scientific name: Oxyuranus scutellatusFamily: ElapidaeRange: Northern and eastern Australia, southern Papua New GuineaAverage length: 6.6–9.8 ft (2.0–3.0 m)Venom yield per bite: 58–120 mg (dry weight)
Ad · in-feed
4
Dubois' Sea Snake (Aipysurus duboisii)
Dubois' sea snake, also called the reef shallows sea snake, has the most potent venom of any sea snake at an LD50 of 0.144 mg/kg SC. Found in the coral reefs of the Coral Sea, Timor Sea, and Arafura Sea, this sea snake has a primarily neurotoxic venom that causes paralysis and respiratory failure. Like most sea snakes, it is not aggressive and bites typically occur when fishermen accidentally catch them in nets. The venom yield per bite is relatively small, but the potency makes it extremely dangerous.
The common death adder ranks fifth with an LD50 of 0.15 mg/kg SC. Unlike most Australian elapids, the death adder is a viper-like ambush predator that uses a worm-like tail tip to lure prey. It has the longest fangs of any Australian snake and can inject venom from any angle. Its venom is a powerful post-synaptic neurotoxin that causes progressive paralysis. Before antivenom was available, approximately 60% of untreated bites were fatal. The death adder's superb camouflage and ambush hunting strategy make it particularly dangerous to humans who step near it.
Scientific name: Acanthophis antarcticusFamily: ElapidaeRange: Coastal regions of Australia (except far north)Average length: 1.6–3.3 ft (0.5–1.0 m)Venom yield per bite: 35–60 mg (dry weight)
6
Black Mamba (Dendroaspis polylepis)
The black mamba is Africa's most feared snake, with an LD50 of 0.25 mg/kg SC. It is also the fastest land snake, capable of reaching 12 mph (19 km/h), and can grow up to 14 feet (4.3 meters), making it the second-longest venomous snake after the king cobra. Found in savanna and rocky regions of sub-Saharan Africa, the black mamba's venom contains powerful dendrotoxins that block potassium channels in nerves, causing rapid paralysis and respiratory failure. Before antivenom, the fatality rate was nearly 100%. Bites can kill within 20 minutes if untreated.
Scientific name: Dendroaspis polylepisFamily: ElapidaeRange: Sub-Saharan Africa (savanna and rocky regions)Average length: 6.6–9.8 ft (2.0–3.0 m)Venom yield per bite: 100–400 mg (dry weight)
7
Tiger Snake (Notechis scutatus)
The tiger snake has an LD50 of 0.265 mg/kg SC, making it Australia's seventh-most venomous snake. Its venom is a complex cocktail of neurotoxins, myotoxins, procoagulants, and hemolysins that can cause paralysis, muscle breakdown, and bleeding. Found in southern Australia, including Tasmania, the tiger snake is named for its banded cross-body stripes. It is responsible for a significant number of snakebite fatalities in Australia due to its widespread distribution and tendency to stand its ground when threatened.
Scientific name: Notechis scutatusFamily: ElapidaeRange: Southern Australia, including TasmaniaAverage length: 3.9–6.6 ft (1.2–2.0 m)Venom yield per bite: 35–65 mg (dry weight)
8
Beaded Sea Snake (Hydrophis schistosus)
The beaded sea snake, also known as the hook-nosed sea snake, has an LD50 of 0.3 mg/kg SC. Found in the coastal waters of the Indian Ocean and Southeast Asia, it is one of the most venomous sea snakes. Its venom is a potent neurotoxin that causes paralysis and respiratory failure. The beaded sea snake is responsible for a significant number of envenomations in Southeast Asian fishing communities, where snakes are accidentally caught in trawl nets. Its wide distribution and frequent encounters with fishing nets make it one of the most medically significant sea snakes.
Scientific name: Hydrophis schistosusFamily: ElapidaeRange: Indian Ocean, Southeast Asia, northern AustraliaAverage length: 3.0–4.9 ft (0.9–1.5 m)Venom yield per bite: 5–15 mg (estimated)
9
Many-Banded Krait (Bungarus multicinctus)
The many-banded krait has an LD50 of 0.32 mg/kg SC, making it the most venomous krait species. Found in freshwater wetlands and rice paddies across Southeast Asia, southern China, and Taiwan, this nocturnal snake is responsible for numerous human fatalities in rural areas. Its venom contains beta-bungarotoxin, a potent presynaptic neurotoxin that causes progressive paralysis. A distinctive feature of krait envenomation is the delayed onset of symptoms — victims may not feel significant pain from the bite, only to develop respiratory failure hours later.
The king cobra, the world's longest venomous snake at up to 18 feet (5.5 meters), has an LD50 of 0.36 mg/kg SC. While its venom is not the most potent by weight, the king cobra delivers an enormous volume — up to 500 mg per bite, enough to kill an elephant. Its venom contains a complex neurotoxin that causes paralysis and respiratory failure. The king cobra is found in forests across South and Southeast Asia and is known for its distinctive hood and defensive posture. Despite its size and reputation, the king cobra is generally shy and avoids human contact when possible.
Scientific name: Ophiophagus hannahFamily: ElapidaeRange: South and Southeast Asia (forests)Average length: 10.0–14.8 ft (3.0–4.5 m)Venom yield per bite: 200–500 mg (dry weight)
Ad · in-feed
Full comparison
#
Name
Scientific name
Family
Range
Average length
Venom yield per bite
1
Inland Taipan (Oxyuranus microlepidotus)
Oxyuranus microlepidotus
Elapidae
Central-east Australia (semi-arid regions)
5.9–8.2 ft (1.8–2.5 m)
44–110 mg (dry weight)
2
Eastern Brown Snake (Pseudonaja textilis)
Pseudonaja textilis
Elapidae
Eastern and southern Australia, southern Papua New Guinea
4.9–6.6 ft (1.5–2.0 m)
4–13 mg (dry weight)
3
Coastal Taipan (Oxyuranus scutellatus)
Oxyuranus scutellatus
Elapidae
Northern and eastern Australia, southern Papua New Guinea
6.6–9.8 ft (2.0–3.0 m)
58–120 mg (dry weight)
4
Dubois' Sea Snake (Aipysurus duboisii)
Aipysurus duboisii
Elapidae
Coral Sea, Timor Sea, Arafura Sea
2.6–3.9 ft (0.8–1.2 m)
5–10 mg (estimated)
5
Common Death Adder (Acanthophis antarcticus)
Acanthophis antarcticus
Elapidae
Coastal regions of Australia (except far north)
1.6–3.3 ft (0.5–1.0 m)
35–60 mg (dry weight)
6
Black Mamba (Dendroaspis polylepis)
Dendroaspis polylepis
Elapidae
Sub-Saharan Africa (savanna and rocky regions)
6.6–9.8 ft (2.0–3.0 m)
100–400 mg (dry weight)
7
Tiger Snake (Notechis scutatus)
Notechis scutatus
Elapidae
Southern Australia, including Tasmania
3.9–6.6 ft (1.2–2.0 m)
35–65 mg (dry weight)
8
Beaded Sea Snake (Hydrophis schistosus)
Hydrophis schistosus
Elapidae
Indian Ocean, Southeast Asia, northern Australia
3.0–4.9 ft (0.9–1.5 m)
5–15 mg (estimated)
9
Many-Banded Krait (Bungarus multicinctus)
Bungarus multicinctus
Elapidae
Southeast Asia, southern China, Taiwan
3.3–5.9 ft (1.0–1.8 m)
10–20 mg (dry weight)
10
King Cobra (Ophiophagus hannah)
Ophiophagus hannah
Elapidae
South and Southeast Asia (forests)
10.0–14.8 ft (3.0–4.5 m)
200–500 mg (dry weight)
How we ranked this
Snakes are ranked by subcutaneous (SC) LD50 value in mice, measured in milligrams of venom per kilogram of body weight (mg/kg). Lower values indicate more potent venom. Data is sourced from published toxinology research, the Australian Venom Research Unit, the Journal of Toxicology, and WHO venom databases. Where multiple published LD50 values exist for the same species, the lowest (most potent) value is used. Rankings focus exclusively on subcutaneous LD50, which most closely mimics a natural snakebite. Not all species have been tested with the same rigor, and some gaps exist in the peer-reviewed literature.
FAQ
What is the most venomous snake in the world?
The inland taipan (Oxyuranus microlepidotus) of Australia has the most potent venom of any snake, with a subcutaneous LD50 of 0.025 mg/kg. However, the most dangerous snake to humans differs by region — the eastern brown snake causes the most fatalities in Australia, the black mamba in Africa, and the saw-scaled viper in the Middle East and Asia.
Why does Australia have so many of the most venomous snakes?
Australia's isolated evolutionary history allowed elapid snakes to diversify into a wide range of ecological niches without competition from vipers (which are absent from Australia). The continent's harsh, unpredictable climate may have also favored snakes with more potent venom, as a single successful bite becomes more critical when prey is scarce.
What is the difference between venom potency and venom yield?
Venom potency (LD50) measures how toxic the venom is per unit of weight, while venom yield measures how much venom the snake can deliver in a single bite. A snake with moderately potent venom but a very high yield, like the king cobra, can be far more dangerous than a snake with highly potent venom but a low yield.
How does LD50 correlate with human fatality risk?
LD50 in mice is a useful comparison tool but does not perfectly predict human outcomes. Factors such as the snake's venom yield, fang length, bite mechanics, proximity to medical care, and the individual's sensitivity all influence the actual risk. The eastern brown snake, for example, has a lower LD50 than the coastal taipan but causes more human fatalities due to its abundance near populated areas.