What Is the World's Largest Spider by Weight and Size?

The world’s largest spider is the Goliath Birdeater (Theraphosa blondi), a massive tarantula with a leg span reaching up to 12 inches and weighing as much as 6 ounces. This South American arachnid holds the record for both size and mass among all spider species.

Physical Dimensions That Defy Expectations

The Goliath Birdeater’s leg span can exceed the width of a human face, making it wider than a dinner plate. At 6 ounces, it weighs roughly the same as a newborn puppy, giving it substantial heft that you could literally feel if held in both hands. Its fangs alone measure up to 1.5 inches in length—large enough to pierce through a human finger with ease.

This impressive size makes it not just the largest spider by leg span, but also the heaviest spider species on Earth. While other spiders like the Giant Huntsman may have longer legs, none match the Goliath Birdeater’s overall mass and bulk.

Defensive Mechanisms and Behavior

When threatened, this giant employs multiple defense strategies that would make most predators think twice. The spider can launch clouds of barbed urticating hairs from its abdomen, which irritate human eyes and nasal passages for days. If this warning fails, it produces a loud hissing sound by rubbing its leg bristles together—audible from up to 15 feet away.

Despite its intimidating size and defensive capabilities, the Goliath Birdeater is generally not aggressive toward humans. Its venom, while delivered through those impressive fangs, is medically insignificant to healthy adults—no more dangerous than a bee sting.

Diet and Hunting Methods

Contrary to its name, the Goliath Birdeater rarely eats birds. Instead, it primarily hunts earthworms, frogs, insects, and other small ground-dwelling creatures in the rainforests of South America. The spider employs a gruesome but effective feeding method: it injects digestive enzymes into its prey, liquefying the internal organs and tissues, then drinks the resulting fluid, leaving behind only an empty husk.

This feeding strategy allows the spider to consume prey that might otherwise be too large or tough to eat conventionally, maximizing its nutritional intake in the resource-competitive rainforest environment.

Habitat and Cultural Significance

The Goliath Birdeater inhabits the rainforests of Venezuela, Brazil, Guyana, and Suriname, where it lives in burrows or under logs and rocks. Interestingly, some indigenous communities in Venezuela and Brazil consider these massive spiders a delicacy, roasting them over fires and describing the taste as similar to shrimp or crab.

This cultural acceptance demonstrates how perspectives on these impressive arachnids vary dramatically across different societies, from objects of fear to sources of sustenance.