9 Biggest Spiders in the World: A Journey into the Gigantic

goliath birdeater spider
The Goliath birdeater spider (Theraphosa blondi) weighs in as the world's largest and heaviest spider. Yikes! PetlinDmitry/Shutterstock

In the fascinating and often misunderstood world of arachnids, the biggest spiders in the world stand as giants among their kin, sparking both awe and apprehension. These eight-legged creatures, ranging from the Goliath birdeater to the giant huntsman, showcase an astonishing diversity in size, habitat and behavior.

While they may incite fear due to their impressive dimensions, these spiders play crucial roles in their ecosystems and have become subjects of significant scientific interest and study.

Let's take a closer look at some of the biggest arachnids around the globe and learn about their behaviors and ecosystems.

Measuring Spiders

When you're measuring giant spiders, it basically comes down to two things: how long their bodies are and how wide they can stretch their legs.

First up, we've got body length. This is like measuring a person from head to toe. You start at the spider's head, or the prosoma as the science folks call it, and go all the way to the end of its abdomen, the opisthosoma. This gives you the size of the spider's main body — without the legs. It's a useful measurement for scientists who need to compare different spiders.

Then there's the leg span, which is kind of the more dramatic way to measure spiders, especially the big ones like tarantulas.

Imagine stretching out a spider’s legs as far as they can go and measuring from the tip of one leg to the tip of the leg on the opposite side. This number is usually bigger and a bit more eye-catching, but it can change a bit if the spider curls up or loses a leg.

Goliath birdeater spider
Goliath birdeater spider. Jasius / Getty Images

1. Goliath Birdeater Spider

Well, this spider (sometimes misnomered the Goliath bird-eating spider) is huge, but it doesn't eat birds often enough to warrant the name. But at least half of the Goliath birdeater's name is accurate because it's a real giant.

It's the world's largest spider — and the heaviest. Native to South America's rainforests, the Goliath birdeater weighs as much as a hockey puck, with a body the size of a midsized smartphone and a leg span reaching up to 12 inches (30 centimeters).

Although it has an intimidating name and size, this spider species is relatively harmless to humans. Its venom isn't highly toxic to us, so, to protect itself, it employs unique defensive tactics.

When threatened, it releases irritant hairs from its abdomen and makes a distinct sound by rubbing its legs together — a process known as stridulation, similar to the chirping of crickets. It can be heard by humans and animals alike from up to 15 feet (4.6 meters) away.

While the birdeater rarely preys on birds, insects, frogs and small mammals are on the menu for this behemoth. As a ground hunter, it uses its potent neurotoxin to immobilize prey on the ground before dragging it back to its burrow for a private feast. The neurotoxin liquefies the prey's insides, which the spider then consumes.

In the exotic pet trade, these spiders are valued for their size and longevity, with females living up to 20 years — significantly longer than their male counterparts, which can live up to six years in captivity.

Giant huntsman spider
Giant huntsman spider. Jeroen Mikkers / Shutterstock

2. Giant Huntsman Spider

This leggy spider might not be as famed as its birdeater cousin, but it's a record-breaker in its own right. The huntsman ties for the title of the largest leg span of any spider in the world — a staggering 12 inches (30 centimeters).

Discovered in a cave in Laos, this huntsman doesn't build webs. Instead, it roams and hunts, true to its name, showcasing incredible speed and agility.

Unlike many of its kin, the huntsman spider prefers cave walls to forest floors, making it a fascinating subject for arachnologists. While its appearance might seem intimidating, this spider is generally shy and avoids human contact. Its venom, though potent enough to subdue its prey, is not considered dangerous to humans.

So, while its size might be awe-inspiring, huntsman spiders are more a wonder of nature than a threat, playing a vital role in controlling insect populations in its habitat.

Brazilian salmon pink birdeater
Brazilian salmon pink birdeater. Mark Newman / Getty Images

3. Brazilian Salmon Pink Birdeater

The Brazilian salmon pink birdeater (Lasiodora parahybana) is a sight to behold in the spider world. This species is one of the most impressive tarantulas, renowned for its significant size. With a leg span that can reach up to 10 inches (25.4 centimeters), it's like encountering a dinner plate scuttling across the forest floor.

Originating from northeastern Brazil, it's not just their size that's striking, but also their beautiful, salmon-pink hair, giving them a unique flair among tarantulas.

Despite their daunting size and appearance, they're known to be relatively docile. They might have intimidating fangs, but their venom is mild to humans, making them more of a gentle giant in the spider realm.

4. Hercules Baboon Spider

The Hercules baboon spider (Hysterocrates hercules) is a bit of an enigma in the spider world, and a name like "Hercules" definitely sets some high expectations.

Native to Africa, this species is rumored to be one of the largest tarantulas in the world, yet it remains shrouded in mystery. Sightings are rare, making it something of a legend among arachnid enthusiasts.

Its supposed size, with a leg span that could rival the largest of spiders, adds to its mythical status. Some estimates suggest that its leg span could reach around 8 inches (20.3 centimeters) or more, but these figures should be taken with caution as they are based on limited observations and anecdotal reports

Despite its formidable name, the Hercules spider is more reclusive than aggressive. It prefers to stay hidden, making its true size and habits subjects of speculation. If you're lucky enough to spot one, you're witnessing a rare moment in the wild.

Colombia tarantula
Colombia tarantula. Robert Oelman / Getty Images

5. Colombian Giant Tarantula

The Colombian giant redleg tarantula (Megaphobema robustum) is quite the showstopper in the world of arachnids. Hailing from the rainforests of Colombia, this tarantula isn't just giant by name.

With a leg span that can stretch up to 8 inches (20.3 centimeters), it's like encountering a small pizza on eight legs. What sets this species apart, aside from its impressive size, is its striking appearance.

The Colombian redleg boasts a velvety black body contrasted with vibrant reddish hairs, making it a visual treat. Despite its daunting presence, it's known to be more of a gentle giant, with a calm demeanor, unless provoked. It's a burrower by nature, creating impressive tunnels as homes.

While it might seem fearsome, this tarantula plays an important ecological role, and its venom, though effective on small prey, poses little threat to humans.

6. Poecilotheria Rajaei

The Poecilotheria Rajaei, discovered relatively recently in Sri Lanka, adds a dazzling flair to the spider world. Known for its strikingly beautiful and intricate patterns, this species exhibits a blend of geometric designs that are both mesmerizing and a bit intimidating.

Its leg span can reach up to 8 inches (20.3 centimeters), making it a sizable entry in the big spider league.

What's really fascinating about Poecilotheria Rajaei, aside from its size, is its arboreal nature. Unlike many large, ground-dwelling tarantulas, this species prefers the lofty heights of trees. Though it's a sight to behold, it's wise to admire from a distance, as its venom is potent.

7. Brazilian Giant Tawny Red Tarantula

The Brazilian giant tawny red tarantula (Grammostola anthracina) is another star in the tarantula universe. This South American native, particularly found in Brazil, boasts a leg span that can reach up to 7 inches (17.8 centimeters) — large enough to make even non-arachnophobes uncomfortable.

Its most striking feature is its tawny-red coloration, which gives it a regal and intimidating appearance. But despite its fearsome look, this tarantula is known for its relatively docile nature, often surprising those who expect a more aggressive demeanor.

It's a burrowing species, preferring to spend its time in well-crafted underground lairs. For spider enthusiasts, the tawny red tarantula is a sought-after species, mostly due to its size, beauty and manageable temperament.

8. Colombian Blue Bloom Tarantula

The Colombian blue bloom tarantula (Pamphobeteus nigricolor), a dazzling inhabitant of the Colombian rainforests, stands out with its striking blue coloration, a hue that's not just rare but also mesmerizing. With a leg span that can reach up to 7 inches (17.8 centimeters), it's not only a visual spectacle but also boasts a significant size.

Known for its relatively docile nature, the Colombian blue bloom can still be a handful due to its skittishness, making it a captivating yet challenging pet. Ideal for those who appreciate beauty from a distance, this tarantula is more of a display species, thriving in a tranquil environment with minimal interference.

Its preference for solitude and the unique charm it brings to a terrarium make the Colombian tarantula a cherished species among tarantula aficionados.

Colombian lesserrblack tarantula
Colombian lesserrblack tarantula. tempisch / Shutterstock

9. Colombian Lesserblack Tarantula

The blue bloom isn't the only massive tarantula from the rainforests of Colombia. The lesserblack tarantula (Xenesthis immanis) truly stands out in the world of arachnids.

With a leg span reaching up to 7 inches (17.8 centimeters), its size alone is enough to capture anyone's attention. But it's the stunning visual contrast of its deep black body adorned with vibrant patches that makes it a true spectacle.

Despite its imposing appearance, the lesserblack is known for a relatively docile temperament, making it a sought-after species among tarantula enthusiasts and keepers. However, its size and strength demand respect and careful handling.

In captivity, these tarantulas can live for a significant amount of time. Females generally live longer than males, with lifespans ranging from 12 to 20 years for females and up to five years for males.

Camel spider
Camel spider. Dmitry Fch / Shutterstock

Honorable Mention: Camel Spider

Ah, the camel spider, a creature shrouded in wild myths and hair-raising tales from desert battlegrounds. While not true spiders, these members of the Solifugae order are often lumped into the category due to their fearsome appearance.

Found in desert regions, they can reach sizes of about 6 inches (15.2 centimeters), which is quite large for a creature often mistaken for a spider.

Camel spiders are known for their formidable jaws, which are disproportionately large compared to their body size, and their astonishing speed, darting across desert sands.

Despite popular legends, they are neither venomous nor do they chase humans. Instead, these fascinating creatures are adept hunters of insects and small animals, playing an important role in their arid ecosystems.

Now That's Interesting

The egg sac of a Goliath birdeater is about the size of a tennis ball.

Original article: 9 Biggest Spiders in the World: A Journey into the Gigantic

Copyright © 2023 HowStuffWorks, a division of InfoSpace Holdings, LLC, a System1 Company