As of late 2024, the question of the world's biggest spider does not have a single, simple answer. The title is split between two colossal arachnids, depending on whether you measure by sheer weight and body mass or by the terrifying, sprawling length of its legs. This deep dive will resolve the debate, revealing the two current record-holders and the third massive species that often completes the list of the largest spiders on Earth. The scientific consensus is that the biggest spider by mass is the *Theraphosa blondi*, while the biggest by leg span is the *Heteropoda maxima*. These giants dwarf most other tarantulas and huntsman species, possessing unique characteristics, powerful defenses, and habitats far from human civilization, making them subjects of intense curiosity and fear.
The King of Mass: Goliath Birdeater (Theraphosa blondi)
The undisputed champion for overall size and bulk is the
Goliath Birdeater (*Theraphosa blondi*). Found in the rainforests of northern South America, this tarantula is a true behemoth that holds the Guinness World Record for the largest spider by mass.
Goliath Birdeater: Profile and Record Stats
- Scientific Name: *Theraphosa blondi*
- Record Title: Largest Spider by Mass and Body Length
- Maximum Mass: Up to 175 grams (6.2 oz)
- Maximum Body Length: Up to 13 cm (5.1 inches)
- Maximum Leg Span: Up to 30 cm (12 inches)
- Habitat: Swampy, marshy rainforests of Venezuela, Guyana, Suriname, and northern Brazil.
The body of a Goliath Birdeater is roughly the size of a large fist, making it incredibly heavy for an arachnid. Its sheer bulk gives it a terrifying, heavy-bodied appearance that is distinct from its leg-span rival.
Diet, Behavior, and Defense Mechanisms
Despite its common name, the Goliath Birdeater rarely preys on birds. Its diet primarily consists of large insects, frogs, toads, lizards, and occasionally small rodents and snakes. They are nocturnal, terrestrial spiders that live in deep burrows lined with silk. When threatened, the Goliath Birdeater employs two primary defense mechanisms:
- Urticating Hairs: It will rub its abdomen to release a cloud of tiny, barbed hairs that cause severe irritation to the skin, eyes, and respiratory tract of a predator.
- Fangs: The fangs can be up to 2 cm (0.8 inches) long, capable of inflicting a painful bite and large puncture wounds. While its venom is not lethal to humans, the bite is comparable to a wasp sting and can cause swelling and pain.
The King of Leg Span: Giant Huntsman Spider (Heteropoda maxima)
If the Goliath Birdeater is the heavyweight champion, the
Giant Huntsman Spider (*Heteropoda maxima*) is the featherweight champion, holding the record for the largest leg span of any known spider.
Giant Huntsman Spider: Profile and Record Stats
- Scientific Name: *Heteropoda maxima*
- Record Title: Largest Spider by Leg Span
- Maximum Leg Span: Up to 30 cm (12 inches)—and sometimes slightly more, earning it the record.
- Body Length: Approximately 4.6 cm (1.8 inches)
- Habitat: Caves in Laos, Southeast Asia.
The Giant Huntsman was only discovered in 2001 in a cave system in Laos. Its legs are incredibly long and slender compared to its body, giving it a much flatter and more elongated profile than the bulky tarantulas.
The Fastest Spider on Earth
The Huntsman family is known for its speed, and the Giant Huntsman is no exception. It is one of the fastest spiders on the planet, capable of moving up to 1 meter (3 feet) per second. This incredible speed is crucial to its hunting strategy, as it is a nomadic hunter rather than a web-builder. Unlike the Goliath Birdeater, which is a burrowing tarantula, the Giant Huntsman uses its flat body to squeeze into tight rock crevices and under loose bark. Its diet consists mainly of large insects, though it will opportunistically take small vertebrates. Its venom is not considered medically significant to humans, but its speed and enormous size make an encounter a startling experience.
The Popular Third Contender: Brazilian Salmon Pink Birdeater (Lasiodora parahybana)
The third species that consistently ranks among the world's largest is the
Brazilian Salmon Pink Birdeater (*Lasiodora parahybana*). While it doesn't hold a world record, it is a magnificent giant and one of the most popular large tarantulas kept in the exotic pet trade.
Brazilian Salmon Pink Birdeater: Profile and Key Facts
- Scientific Name: *Lasiodora parahybana*
- Maximum Leg Span: Typically 8 to 10 inches (20 to 25 cm)
- Habitat: Forest floor of eastern Brazil.
- Lifespan: Females can live up to 15 years in human care.
This species is easily recognizable by its dark coloration and the striking long, pinkish-red hairs (setae) that give it the "salmon pink" part of its name. Its size is comparable to the Goliath Birdeater, often rivaling it in weight, though typically falling just short of the record.
A Giant in the Pet Trade
The Brazilian Salmon Pink Birdeater is highly sought after by hobbyists due to its impressive size, relatively docile temperament, and longevity. However, like all tarantulas, it can be defensive. It uses the same urticating hair defense mechanism as the Goliath Birdeater, which can cause significant irritation. Its impressive size makes it a powerful predator in its native environment, feeding on anything it can overpower, from large insects to small mammals. They prefer warm and humid environments, with temperatures between 76 to 84 degrees Fahrenheit and high humidity levels.
Key Differences and Entity Summary
The debate over the "biggest spider" is ultimately a matter of definition. Both the Goliath Birdeater and the Giant Huntsman Spider are massive, but they represent two different forms of gigantic arachnids.
| Entity | Goliath Birdeater (*Theraphosa blondi*) | Giant Huntsman Spider (*Heteropoda maxima*) |
| Record Held | Heaviest/Largest by Mass | Largest by Leg Span |
| Maximum Size | 175g Mass / 12 in Span | ~30 cm (12 in) Span |
| Location | Northern South America (Guyana, Brazil) | Laos, Southeast Asia |
| Body Type | Bulky, Heavy, Terrestrial | Flat, Slender, Cave-Dwelling |
| Movement | Burrowing, slower | Extremely Fast (1 m/s) |
| Defense | Urticating Hairs and Large Fangs | Speed and Venom |
Other notable large spider entities that are often mentioned in the same breath as the top three include the
Brazilian Giant Tawny Red Tarantula (*Grammostola anthracina*), the
King Baboon Spider (*Pelinobius muticus*), and the
Colombian Giant Black Tarantula (*Xenesthis immanis*). These species further illustrate the incredible diversity and size range within the *Araneae* order, proving that the world of arachnids is full of breathtaking giants.
