Huntsman spiders, members of the family Sparassidae (formerly Heteropodidae), catch their prey by hunting rather than in webs. They are also called giant crab spiders because of their size and appearance. Larger species sometimes are referred to as wood spiders, because of their preference for woody places (forests, mine shafts, woodpiles, wooden shacks). In southern Africa the genus Palystes are known as rain spiders or lizard-eating spiders. Commonly, they are confused with baboon spiders from the Mygalomorphae infraorder, which are not closely related.

More than a thousand Sparassidae species occur in most warm temperate to tropical regions of the world, including much of Australia, Africa, Asia, the Mediterranean Basin, and the Americas.

Several species of huntsman spider can use an unusual form of locomotion. The wheel spider (Carparachne aureoflava) from the Namib uses a cartwheeling motion which gives it its name, while Cebrennus rechenbergi uses a handspring motion.

Members of the Sparassidae are native to tropical and warm temperate regions worldwide. A few species are native to colder climates, like the green huntsman spider (Micrommata virescens) which is native to Northern and Central Europe. Some tropical species like Heteropoda venatoria (Cane huntsman) and Delena cancerides (Social huntsman) have been accidentally introduced to many subtropical parts of the world, including New Zealand (which has no native sparassid species).

Sparassids are eight-eyed spiders. The eyes appear in two largely forward-facing rows of four on the anterior aspect of the prosoma. Many species grow very large – in Laos, male giant huntsman spiders (Heteropoda maxima) attain a legspan of 25–30 centimetres (9.8–11.8 in).

People unfamiliar with spider taxonomy commonly confuse large species with tarantulas, but huntsman spiders can generally be identified by their legs, which, rather than being jointed vertically relative to the body, are twisted in such a way that in some attitudes the legs extend forward in a crab-like fashion. It is also commonly confused for a brown recluse spider, due to their shared coloring. However, brown recluse venom is significantly dangerous to humans, while that of the huntsman spider is less so.

On their upper surfaces the main colours of huntsman spiders are inconspicuous shades of brown or grey, but many species have undersides more or less aposematically marked in black-and-white. Their legs bear fairly prominent spines, but the rest of their bodies are smoothly furry. They tend to live under rocks, bark and similar shelters, but human encounters are common in sheds, garages and other infrequently-disturbed places. The banded huntsman (Holconia) is large, grey to brown with striped bands on its legs. The badge huntsman (Neosparassus) is larger still, brown and hairy. The tropical or brown huntsman (Heteropoda) is also large and hairy, with mottled brown, white and black markings. The eyesight of these spiders is not as good as that of the Salticidae (jumping spiders). Nevertheless, their vision is quite sufficient to detect approaching humans or other large animals from some distance.

They can be distinguished from other spider families by their appearance, as other spiders similar to them are smaller in size. They are often confused for tarantulas due to their hairy nature, but can easily be distinguished by their laterigrade legs, similar to those of crabs. Members of this family are also typically less bulky than tarantulas. They possess two claws, as is the case for most spiders that actively hunt their prey. If this is not enough to fully identify them, they also possess eight eyes divided into two regular rows.