The World's Largest Spider: A Comparison Based on Weight and Leg Span

Essential Facts

In the fascinating and often misunderstood realm of arachnids, the largest spider in the world stands out among its colossal relatives. From the Goliath birdeater to the Colombian lesserblack tarantula, these massive eight-legged creatures exhibit remarkable diversity in size, habitat, and behavior.

Despite their intimidating size, these spiders are essential to their ecosystems and have garnered significant attention from scientists and researchers for their ecological roles.

9 Largest Spiders on the Planet

Let’s explore some of the world’s largest arachnids, delving into their unique behaviors and the ecosystems they inhabit.

1. Goliath Birdeater Spider

This spider, often mistakenly called the Goliath bird-eating spider, is indeed massive, though it rarely consumes birds to justify its name. However, the 'Goliath' part is fitting, as it is truly a colossal arachnid.

As the largest and heaviest spider globally, this Goliath inhabits South America's rainforests. It weighs as much as a hockey puck, with a body comparable to a medium-sized smartphone and a leg span stretching up to 12 inches (30 centimeters).

Is the Goliath Birdeater Dangerous?

Despite its fearsome name and enormous size, this face-sized tarantula poses little threat to humans due to its gentle nature. Its venom is not highly dangerous to people, so it relies on unique defense mechanisms to protect itself.

Instead of using venom when threatened, it ejects urticating hairs from its abdomen. These barbed hairs can lodge into the skin of predators or humans who try to handle it, causing intense irritation and prompting them to retreat.

The tarantula also produces a unique sound by rubbing its hind legs together, a behavior called stridulation, akin to the chirping of crickets. This sound can be heard by both humans and animals from distances of up to 15 feet (4.6 meters).

What Do Goliath Birdeaters Eat?

This giant spider has a varied diet, feeding on insects, frogs, small mammals, and occasionally birds, making it a versatile predator in its habitat.

As a ground-dwelling predator, it employs its powerful neurotoxin to paralyze prey before transporting it to its burrow for consumption. The neurotoxin breaks down the prey's internal tissues, allowing the spider to feed on the liquefied remains.

Birdeaters as Pets

These spiders are highly sought after in the exotic pet trade due to their impressive size and long lifespan. Female birdeaters can live up to 20 years, far outlasting males, which typically survive for about six years in captivity.

2. Giant Huntsman Spider

This long-legged spider may not be as well-known as the birdeater, but it holds its own record. The huntsman shares the title for the largest leg span of any spider globally, measuring an impressive 12 inches (30 centimeters).

Found in a Laotian cave, this huntsman spider doesn’t rely on webs. Instead, it lives up to its name by actively roaming and hunting, displaying remarkable speed and dexterity. Unlike many spiders, it favors cave walls over forest floors, making it a captivating subject for arachnologists.

Are Giant Huntsman Spiders Dangerous?

Despite its intimidating appearance, this spider is typically reclusive and avoids humans. Its venom, while effective against prey, poses no significant threat to people.

While the huntsman spider’s size may be astonishing, it is more a marvel of nature than a danger, serving a crucial role in managing insect populations within its ecosystem.

A Desert Cousin

If you explore the deserts of the Middle East, you might encounter a smaller relative of this species, the sand-dwelling huntsman spider. This nocturnal creature spends its days hidden beneath sand dunes, emerging at night to hunt small ground-dwelling animals.

3. Brazilian Salmon Pink Birdeater

The Brazilian salmon pink birdeater (Lasiodora parahybana) is a remarkable specimen in the arachnid kingdom. This tarantula stands out as one of the most striking species, celebrated for its substantial size.

Boasting a leg span of up to 10 inches (25.4 centimeters), encountering one is akin to seeing a dinner plate moving across the forest floor.

Native to northeastern Brazil, these spiders captivate not only with their size but also with their stunning salmon-pink hairs, setting them apart from other tarantulas.

Despite their imposing size and fearsome look, birdeaters are generally calm. While their fangs may appear threatening, their venom is mild to humans, earning them the reputation of gentle giants in the spider world.

Beware the Brazilian Wandering Spider

In Brazil, you might also encounter the Brazilian wandering spider, a species that roams the jungle floors of South America. Its bite is not only painful but can also be hazardous to humans.

This spider family boasts a leg span of up to 7 inches (18 centimeters) and is often called the banana spider due to its habit of hiding in fruit shipments, potentially endangering unsuspecting dock workers.

4. Hercules Baboon Spider

The Hercules baboon spider (Hysterocrates hercules) is a mysterious figure in the arachnid world, and its name, evoking the strength of Hercules, certainly raises expectations.

Originating from central African nations like Nigeria, this species is believed to be one of the largest tarantulas globally, yet it remains elusive. Rare sightings have turned it into a legend among spider enthusiasts.

Its rumored size, with a leg span potentially matching the largest spiders, contributes to its legendary status. Estimates suggest a leg span of around 8 inches (20.3 centimeters) or more, though these claims are based on limited evidence and should be approached with skepticism.

Despite its intimidating name, the Hercules spider is more elusive than aggressive. It tends to remain hidden, leaving its true size and behavior open to speculation. Spotting one in the wild is a rare and remarkable experience.

Another Baboon Spider

Comparable in size and looks to this species is the king baboon spider, which inhabits deep burrows beneath the grasslands of East Africa. It can produce a chirping sound by rubbing its legs together, similar to a cricket.

This sound serves as a warning to intruders, signaling that they are entering its striking range.

5. Colombian Giant Tarantula

The Colombian blue bloom tarantula (Pamphobeteus nigricolor), a stunning resident of Colombia's rainforests, captivates with its vibrant blue hue. With a leg span reaching up to 7 inches (17.8 centimeters), it combines visual allure with impressive size.

While generally docile, the Colombian blue bloom can be unpredictable due to its nervous temperament, making it an intriguing but demanding pet. Best suited for those who admire its beauty from afar, this tarantula excels as a display species, thriving in calm environments with little disturbance.

Its love for solitude and the unique appeal it adds to any terrarium make the Colombian tarantula a favorite among tarantula enthusiasts.

9. Colombian Lesserblack Tarantula

The blue bloom isn’t the only giant tarantula from Colombia’s rainforests. The lesserblack tarantula (Xenesthis immanis) is a standout in the arachnid world.

With a leg span of up to 7 inches (17.8 centimeters), its sheer size is attention-grabbing. However, it’s the striking contrast of its jet-black body with vivid patches that truly makes it a visual marvel.

Despite its formidable look, the lesserblack is relatively calm, making it a favorite among tarantula enthusiasts. That said, its size and power require cautious and respectful handling.

In captivity, these tarantulas can enjoy a long lifespan. Females typically outlive males, with lifespans ranging from 12 to 20 years, while males usually live up to five years.

Measuring Spiders by Body Length

When measuring giant spiders, two key factors come into play: the length of their bodies and the span of their legs.

First, there’s body length. This is akin to measuring a person from head to toe. You start at the spider’s head, or prosoma as scientists refer to it, and measure to the end of its abdomen, known as the opisthosoma. This provides the size of the spider’s body, excluding its legs.

This measurement is particularly useful for scientists comparing different spider species. The most robust spiders in this category are typically members of the tarantula family.

Measuring Spiders by Leg Span

Leg span is the more visually striking method of measuring spiders, particularly large species like tarantulas. This involves extending a spider’s legs to their fullest and measuring from the tip of one leg to the tip of the opposite leg.

This measurement tends to be larger and more impressive, though it can vary slightly if the spider curls up or loses a limb.