Biggest Spider in the World: Goliath Birdeater vs Giant Huntsman

The Goliath birdeater (Theraphosa blondi) holds the title for the world’s heaviest spider, tipping scales at up to 175 grams. This article sorts fact from fiction on the biggest spiders on Earth, compares mass against leg span, and separates genuine record-holders from exaggerated claims.

Heaviest spider: Goliath birdeater · Largest leg span: Giant huntsman spider – 30 cm · Goliath leg span record: 28 cm · Habitat: Northern South America · Family: Tarantula (Theraphosidae)

What is the biggest spider ever recorded?

The answer depends entirely on how you measure “biggest” — and that’s where most articles get it wrong. Two spiders compete for the crown, but they win in different categories.

Largest by body mass

The Goliath birdeater (Theraphosa blondi) takes the prize for heaviest spider on the planet, with a verified weight reaching up to 175 grams. That’s roughly the mass of a small hamster or a newborn kitten. For comparison, the average tarantula weighs under 30 grams. The heaviest recorded specimen was a two-year-old captive named Rosi, bred by Robert Bustard and reared by Brian Burnett, which weighed 170 grams in February 1998.

Guinness World Records confirms that Theraphosa blondi is “the world’s largest known spider by mass.” This is not an estimate — it’s a measured fact backed by museum documentation and multiple verifications.

Largest by leg span

The giant huntsman spider (Heteropoda maxima) wins the leg span category outright. Extra-large specimens measure up to 30 centimeters toe-to-toe — that’s roughly the length of a standard ruler or a large dinner plate. According to Discover Magazine, these spiders have a body length of about 2 inches, yet their legs span 12 full inches. Orkin’s pest control data confirms the same 12-inch leg span measurement.

The giant huntsman’s legs are notably crablike, with twisted joints that allow it to squeeze into narrow cave crevices in Laos, Southeast Asia — its native habitat.

Record specimens found

Historical record-holders tell the story of how spider measuring has evolved. In April 1965, the Pablo San Martin Expedition collected a Goliath birdeater specimen at Rio Cavro, Venezuela, with a leg span of 28 centimeters. Guinness World Records documents this specimen as the first verified giant.

Some Goliath birdeater individuals reportedly match the 30-centimeter leg span, though these claims remain less consistently verified than the giant huntsman’s measurements. Discover Wildlife notes that the giant huntsman is typically larger on average in leg span than the Goliath.

Is the Goliath birdeater friendly to humans?

Despite its formidable name and appearance, the Goliath birdeater is not typically aggressive toward humans. Here’s what you need to know about living alongside — or avoiding — the world’s heaviest spider.

Behavior toward humans

The Goliath birdeater belongs to the tarantula family (Theraphosidae), which is known more for dramatic posturing than actual attacks. When threatened, these spiders typically rear up and display their fangs — a warning display that often suffices. Their first instinct is to retreat rather than engage.

Found in rainforests of northern South America — specifically Venezuela, Brazil, Guyana, and French Guiana — according to Guinness World Records, these spiders live in burrows they excavate in the forest floor. They are nocturnal hunters, preying primarily on insects, rodents, and occasionally small birds.

Defensive responses

The Goliath birdeater has two defensive weapons beyond its fangs. First, it possesses urticating hairs — tiny barbed bristles that cause skin and eye irritation if flicked toward a perceived threat. Second, its venom, according to Orkin, is “comparable to a wasp sting” — painful but not medically significant for healthy adults.

The spider’s bite delivers venom that causes localized pain and discomfort, but no fatalities have been recorded from Goliath birdeater bites.

Pet trade suitability

Goliath birdeaters appear occasionally in the exotic pet trade, though they are not ideal for beginners. Their size means they need appropriately sized enclosures, and their defensive hair-flicking behavior can be problematic for handlers. Those interested should research local regulations, as tarantula ownership laws vary by jurisdiction.

What are the top 10 biggest spiders in the world?

Ranking the world’s largest spiders requires establishing clear criteria first. Body mass and leg span produce different winners, so a fair ranking considers both metrics.

Ranking criteria

Spider size rankings typically rely on maximum leg span as the primary metric, with body mass as a secondary qualifier. The Discover Wildlife publication notes several competing species, including the sand-dwelling huntsman (Cerbalus aravaensis) from Israel and Jordan with a leg span up to 14 centimeters — impressive but far short of the 30-centimeter giant huntsman.

A complete top-10 list by leg span would include: giant huntsman (30 cm), Goliath birdeater (28-30 cm depending on specimen), Cerbalus aravaensis (14 cm), and several other huntsman and tarantula species with progressively smaller spans.

Key species profiles

Beyond the top two contenders, notable large spiders include the pinkfoot goliath (Theraphosa apophysis), which may rival its famous relative but remains less documented. Discover Magazine describes the Goliath birdeater as “close to 5 inches body length with an 11-inch leg span” — roughly the size of a small dinner plate.

The giant huntsman, according to Orkin’s pest control research, moves at up to 3 feet per second — remarkably fast for its size and roughly equivalent to a human jogging pace. This speed helps it hunt cave-dwelling prey in its Laos habitat.

Is the biggest spider in the world poisonous?

The word “poisonous” technically misapplies to spiders — they possess venom, which they inject through fangs. Understanding this distinction matters when assessing actual risk.

Venom details

The giant huntsman’s venom is not a major threat to humans, according to Discover Magazine. Like most spider venoms, it works primarily to immobilize insect prey. The Goliath birdeater’s venom, according to Orkin, is comparable to a wasp sting in potency.

Neither spider is considered medically significant to humans, though individual allergic reactions can always occur.

Danger to humans

For healthy adults, a bite from either the Goliath birdeater or giant huntsman would cause localized pain and potentially mild swelling — comparable to a hornet sting. The more realistic concern is the Goliath birdeater’s urticating hairs, which can cause significant skin and eye irritation if the spider feels threatened and flicks them.

No deaths have been documented from either species. Guinness World Records confirms the Goliath birdeater “preys on insects, rodents, occasionally birds” — not humans.

Goliath birdeater: Largest tarantula?

The name “Goliath birdeater” sounds like something from a horror film, but its origins are genuinely historical. Understanding where this name came from reveals how science and myth have intertwined.

Size records

The Goliath birdeater’s scientific name is Theraphosa blondi, and it belongs to the Theraphosidae family — the tarantulas. With a body length up to 13 centimeters and leg span reaching 28 centimeters in documented specimens, it is unequivocally the largest tarantula by mass and one of the largest by leg span.

Guinness World Records has consistently recognized Theraphosa blondi as the world’s largest spider by mass since record-keeping began. The Rosi specimen from February 1998 measured 28 centimeters leg span and 170 grams — still the most thoroughly documented individual.

Myths debunked

The name “bird-eating” comes from an 18th-century engraving depicting a tarantula eating a hummingbird, giving the species its enduring name. In reality, birds are occasional prey items, not primary diet staples. Guinness World Records specifies the Goliath birdeater “preys on insects, rodents, occasionally birds” — the occasional qualifier matters.

In some South American cuisines, the Goliath birdeater is actually considered edible, according to Discover Magazine. This cultural practice contradicts the aggressive predator image and underscores that the spider is more scared of humans than vice versa.

How do the two biggest spiders compare?

Three metrics matter most when comparing the Goliath birdeater and giant huntsman: mass, leg span, and body size. Each metric produces a different winner.

The comparison below summarizes how these two record-holding species measure against each other across key attributes.

The implication is clear: choosing a “winner” depends entirely on your metric. For sheer weight, the Goliath birdeater wins. For leg span, the giant huntsman takes it. For body length, Goliath again claims the trophy.

Regional variations

The Goliath birdeater ranges across northern South America, with populations documented in Venezuela, Brazil, Guyana, and French Guiana. The giant huntsman remains native to Laos, where it was discovered in cave systems and formally identified relatively recently.

These two spiders will never encounter each other in the wild — they evolved on opposite sides of the planet in completely different ecosystems.

“The world’s largest known spider by mass is the goliath bird-eating tarantula (Theraphosa blondi).”

— Guinness World Records (Official Record Keeper)

“The giant huntsman spider is known as the world’s largest spider by leg span, measuring up to a whopping 30cm toe-to-toe.”

— Discover Wildlife (Wildlife Publication)

“It’s been almost lovingly compared to the size of a small puppy, which this tarantula could probably eat if it ever stumbled upon one.”

— Discover Magazine (Science Magazine)

The pattern is straightforward: the Goliath birdeater and giant huntsman represent the two valid ways to measure “biggest spider” — by mass and by leg span. They are not rivals competing for a single title. Both deserve recognition as nature’s most impressive arachnids, but for different reasons.

Related reading: Dog rescue near me

While the giant huntsman claims the widest leg span at 30 cm, the Goliath Birdeater size facts underscore why the Goliath birdeater reigns as the heaviest at 175 grams.

Frequently asked questions