How Fast Is a Huntsman Spider?

Huntsman spiders are among the fastest spiders on the planet, with measured average speeds reaching about 0.18 meters per second and burst speeds that can be considerably higher. In controlled lab settings, huntsman spiders cover ground at roughly two to nine body lengths per second, which is what makes them look so startlingly quick when they dart across a wall or ceiling. The real story of their speed, though, involves sideways-pointing legs, hydraulic fluid pumped through their joints, and a body plan that trades raw top speed for explosive agility.

What the Lab Measurements Actually Show

Pinning down a single “top speed” for huntsman spiders is harder than it sounds. These animals do not sprint in straight lines on command the way a racehorse leaves a starting gate. Researchers have to film them under controlled conditions and then analyze the footage frame by frame. In a recent study that used computer-assisted gait analysis on huntsman spiders, the average speeds recorded across all trials ranged from 0.04 m/s to 0.18 m/s, which translates to roughly two to nine body lengths per second.¹ That upper end of 0.18 m/s is about 0.65 km/h, which does not sound dramatic until you remember the spider generating it has a body roughly the width of a coin.

Those numbers represent average running speeds, not peak burst velocities. A huntsman spider that senses prey or a threat can accelerate sharply over very short distances. Popular accounts often cite speeds around 1 m/s for the fastest huntsman species, and while that figure is difficult to confirm in peer-reviewed lab conditions, it is consistent with the upper range of body-lengths-per-second values when scaled to the largest species. A giant huntsman with a leg span exceeding 25 centimeters covering nine body lengths per second would be moving much faster in absolute terms than a smaller species doing the same relative speed.

Why They Look Even Faster Than They Are

Part of what makes a huntsman spider’s movement so alarming is not raw speed but the way it moves. Huntsman spiders have laterigrade legs, meaning their legs extend out to the sides like a crab’s rather than pointing forward and backward like most spiders. This gives them a distinctive scuttling motion that allows rapid changes in direction. The same gait-analysis study found that huntsman spiders held an impressively straight line during locomotion, deviating less than five millimeters from a straight path even at higher speeds.¹ That combination of speed and control is what makes them so effective at chasing down prey without a web.

The laterigrade stance also helps explain why huntsman spiders are so good at navigating vertical and inverted surfaces at full speed. A large-scale comparative analysis of running performance across 258 spider species found that a preference for inverted versus upright locomotion did not significantly affect maximum running speed once body size and evolutionary history were accounted for.² In other words, a huntsman running across your ceiling is not meaningfully slower than one running across your floor. The spider’s grip and body mechanics handle gravity without much of a speed penalty.

The Hydraulic Engine Inside Each Leg

Huntsman spiders, like all spiders, do not have extensor muscles in most of their leg joints. Where your knee has muscles that both bend and straighten it, a spider’s equivalent joints rely on internal fluid pressure to extend. The spider pumps hemolymph, its blood-like hydraulic fluid, into channels within the leg to push the joint open. Flexion, on the other hand, is handled by conventional muscles pulling the joint closed. This hybrid system, part muscle and part hydraulic, is what gives spider movement its characteristic snap.

Research on the hunting spider Cupiennius salei has examined how well this hydraulic system handles the demands of fast movement. Using numerical modeling of the tibia-metatarsus joint, researchers found that the channels carrying hemolymph have a diameter that sits in a broad optimum for quick flexion. When the spider deals with small loads comparable to the size of its typical prey, the observed channel dimensions appear tuned to allow the fastest possible joint movement.³ The system is not just functional but fine-tuned: the hydraulic plumbing does not slow down the muscle-driven flexion that matters for catching food.

This matters for understanding huntsman speed because the hydraulic system has inherent limits. Pumping fluid fast enough to keep up with rapid leg cycling is a real engineering challenge for the spider’s body. At very high stride frequencies, coordinating multiple hydraulic joints in sequence becomes the bottleneck, a theme that shows up across spider species when they try to run at their maximum capacity.

Temperature Changes Everything

If you have ever noticed that spiders seem sluggish on cold mornings and alarmingly quick on hot summer nights, you are not imagining things. Spiders are ectotherms, meaning their body temperature tracks their environment, and temperature has a dramatic effect on how fast they can run. A study on sprinting tarantulas found that sprint speed increased 2.5-fold across the tested temperature range. The spiders got faster by increasing stride frequency, not stride length; they took more steps per second rather than longer steps.⁴

That same study found something revealing about the hydraulic system’s limits. At the highest temperatures, where the spiders ran fastest with the highest stride frequencies, the coordination between joints in the same leg broke down. The coupling between the proximal and distal joint angles was significantly lowest at the top speed.⁴ This suggests the hydraulic system hits a ceiling: the spider’s body cannot pump hemolymph fast enough to keep all the joints in perfect sync when stride frequency gets too high. The spider can still run, but its gait becomes less coordinated, and it may be approaching a hard biomechanical limit.

While this particular study used tarantulas rather than huntsman spiders, the underlying hydraulic mechanism is shared across spider families. Huntsman spiders living in tropical climates, where nighttime temperatures stay warm, likely operate closer to their performance ceiling more of the time. A huntsman in a cool temperate garage may be noticeably slower than the same species in a Queensland summer.

Does Size or Sex Affect Speed?

Huntsman spiders show striking differences between males and females, and these differences show up in their locomotion. In the social huntsman Delena cancerides, adult males gain over 30% in leg length at maturity with relatively little increase in body mass. Adult females, by contrast, get larger overall. Despite these very different growth strategies, the maximum running velocity did not differ between age and sex classes.⁵

The picture changes when speed is measured in body lengths per second rather than meters per second. Both immature and adult males had higher relative velocity than females, thanks to their lighter mass.⁵ The males’ long legs give them the same absolute speed as females but with less body to move, so they are covering proportionally more ground per stride relative to their size. For a male huntsman that needs to roam in search of mates, covering more relative distance per stride while maintaining the same top speed is likely an advantage. For a heavier female guarding an egg sac, raw top speed may matter less than other traits.

Across spiders more broadly, the large comparative dataset covering 258 species confirmed that relatively longer legs are associated with stronger running performance after accounting for body size and evolutionary lineage. Interestingly, leg slenderness did not independently predict speed.² Having long legs helps, but having thin, elegant-looking legs does not give any additional boost. What matters is reach, not aesthetics.

How Huntsman Speed Stacks Up Among Spiders

Huntsman spiders belong to the family Sparassidae, and even within that family, speed varies. A molecular phylogeny of Australian huntsman spiders noted that one moderately supported grouping of three genera, Pediana, Beregama, and Typostola, all share “extraordinary locomotory speed” despite being quite different in their overall body shape.⁶ Speed, in other words, appears to have been a consistent selective pressure within the huntsman lineage, favored by evolution even as body plans diverged in other ways.

Among spiders as a whole, the cursorial (actively running) hunters tend to be the fastest, and huntsman spiders sit near the top of that group. For comparison, a study measuring running speed in crab spiders of the genus Philodromus, which are also active hunters, recorded a mean velocity of about 9.4 cm/s, with a single outlier reaching 40 cm/s.⁷ That mean is roughly half the upper average speed recorded for huntsman spiders in the gait-analysis study, and the Philodromus spiders are much smaller. Web-building spiders, which spend most of their time sitting still and waiting, tend to be considerably slower runners when tested on flat surfaces.

The large comparative analysis found that maximum running speed varied substantially both across body masses and among species of similar body mass. Ecological guild, meaning whether a spider is a sit-and-wait predator or an active hunter, showed a modest association with speed. But the strongest predictor was relative leg length, the factor where huntsman spiders excel.²

How Gait Changes With Speed

Huntsman spiders do not simply move their legs faster as they accelerate. Their gait actually shifts. At lower speeds, the stride period is longer and the stance phase, the portion of each stride when a leg is in contact with the ground, takes up a larger fraction of the cycle. As speed increases, both the stride period and the stance phase shorten, with the stance phase consistently occupying between about 50% and 75% of the stride period.¹ This means a fast-moving huntsman has its legs on the ground for a smaller fraction of each step, which is similar to how a trotting horse transitions into a gallop. The spider spends more of each stride in the air or in swing phase, relying on its remaining grounded legs for stability.

The dominant gait pattern at higher speeds is a diagonal rhythm, where legs on opposite sides of the body move in coordinated pairs. This alternating diagonal pattern keeps the spider stable while covering ground quickly. It is also part of why huntsman spiders can maintain such tight trajectories at speed: with legs spread wide and moving in coordinated diagonal pairs, the spider has a broad base of support at all times, even when some legs are mid-swing.

From Spider Legs to Soft Robots

The hybrid hydraulic-muscular system that powers huntsman movement has attracted serious interest from robotics engineers. The appeal is obvious: spiders achieve fast, forceful, lightweight joint actuation without the bulky motors and gearboxes that most robots need. Several research groups have built working prototypes that borrow directly from spider biomechanics.

One approach uses electrostatic forces to locally pressurize a hydraulic fluid inside a soft, segmented structure, mimicking how a spider pressurizes hemolymph to extend a joint. These spider-inspired electrohydraulic soft-actuated joints are lightweight and low-profile, and they can produce fast operation, high forces, and large displacement in a compact package.⁸ A different team took inspiration from the same spider joint mechanics but combined it with a rolling diaphragm design, creating a fluid-driven rotary actuator with direct rotary output.⁹ Both designs share a key insight borrowed from the spider: you do not need separate actuators for extension and flexion if you can route pressurized fluid to do one job while a muscle or spring does the other.

These spider-inspired actuators are still in early development, but the direction is promising for applications where weight and compactness matter: surgical tools, wearable assistive devices, and small-scale exploratory robots. The huntsman spider’s solution to fast, agile locomotion using minimal hardware has turned out to be a blueprint worth copying, even if the engineers working on it would probably prefer not to encounter the original in their lab after dark.

Why the Speed Numbers You See Online Vary So Much

If you search for huntsman spider speed, you will find figures ranging from less than half a meter per second to well over a meter per second, and the disagreement is not just sloppiness. It reflects real differences in what is being measured. Average speed during a lab trial, where a spider may stop, start, and change direction, can be less than a quarter of the peak burst speed during an escape or attack. The species matters enormously too, since the family Sparassidae contains well over a thousand described species ranging from modestly sized to enormous. Temperature during testing, the substrate the spider is running on, whether the spider is motivated by prey or by a perceived threat, and even the spider’s recent feeding history all introduce variability.

The 0.04 to 0.18 m/s average range from the gait-analysis study represents comfortable locomotion under controlled conditions, not a frightened huntsman fleeing for its life. The actual maximum speed of a large, warm, highly motivated huntsman spider in the wild is almost certainly faster, but reliably measuring that is a challenge researchers are still working on. The research that does exist on spider speed across hundreds of species confirms that speed varies hugely even among spiders of similar size, and that huntsman spiders sit in the upper tier of the distribution thanks to their combination of long legs, lightweight build, and active hunting lifestyle.²

1
BioOne Complete. Computer-assisted mode of walking detection and manoeuvrability analysis of huntsman spiders
2
bioRxiv. Evolutionary biomechanics of maximum running speed in spiders (Araneae)
3
Journal of Theoretical Biology. Semi-hydraulic actuation in spider legs: The transport of the hemolymph does not hamper muscle driven leg joint flexion
4
PubMed Central. Effect of temperature on leg kinematics in sprinting tarantulas (Aphonopelma hentzi): high speed may limit hydraulic joint actuation
5
PubMed. Effects on running speed of changes in sexual size dimorphism at maturity on in the cursorial huntsman spider, Delena cancerides (Sparassidae)
6
Molecular Phylogenetics and Evolution. A molecular phylogeny of the Australian huntsman spiders (Sparassidae, Deleninae): implications for taxonomy and social behaviour
7
PLOS ONE. The Aerodynamic Signature of Running Spiders
8
PubMed Central. Spider-Inspired Electrohydraulic Actuators for Fast, Soft-Actuated Joints
9
PubMed Central. A Novel Spider-Inspired Rotary-Rolling Diaphragm Actuator with Linear Torque Characteristic and High Mechanical Efficiency