A dildo is a sex toy, often explicitly phallic in appearance, intended for sexual penetration or other sexual activity during masturbation or with sex partners. Dildos can be made from a number of materials and shaped similarly to an erect human penis. They are typically about the average length of an erect penis, 4–6 inches (10–15 cm), but some may be longer. A dildo’s circumference is typically 4–5 inches (10–13 cm).

A dildo is an object usually designed for sexual penetration of the vagina, mouth, or anus, and is usually solid and phallic in shape. Penis prosthetic aids, known as “extensions”, are not considered dildos. Some include penis-shaped items clearly designed for vaginal penetration, even if they are not true approximations of a penis. An anal dildo is intended for repeated anal penetration, to be distinguished from a butt plug which is flanged with the intent of remaining in place. People of all genders and sexual orientations use these devices for masturbation or other sexual activity.

Materials

Phallus-shaped vegetables and fruits, such as bananas or zucchini or other food items, such as hot dogs or other types of sausages, have been used as dildos in a form of food play. Any object of sufficient firmness and shape can be used like a dildo.^[1]

Conventionally, many dildos are shaped like a human penis with varying degrees of detail, while others are made to resemble the phallus of animals. Not all, however, are fashioned to reproduce the male anatomy meticulously, and dildos come in a wide variety of shapes. They may resemble figures, or simply be practical creations which stimulate more easily than conventional designs. In Japan, many dildos are created to resemble animals or cartoon characters, such as Hello Kitty, so that they may be sold as conventional toys, thus avoiding obscenity laws. Some dildos have textured surfaces to enhance sexual pleasure, and others have macrophallic dimensions including over 12 inches (30.5 cm) long.^[2]

In 2015 research was published into the average size that a sample of women preferred for their partner’s penis. The research used 3D-printed plastic penises of various sizes rather than commercially sold dildos. The average result was around 6.3 inches (16 cm) in length and 4.8 inches (12 cm) in girth.^[3][4] That said, some women may prefer different sizes than the aforementioned, and the 3D printing of dildos gives the option of personalization (allowing to shape and size the dildo to the exact specific dimension that the user wants). Starting in 2012, 3D models of dildos became available for printing by individuals. The advantage of printing at home was not only personalization but also discretion. This, however, did not take off at that time, in part due to the porosity issue of the materials used (which is mainly a problem if no condom is used over the dildo). Some websites have continued to exist however. Besides printing it at home, it is also possible to print it off at a fablab, makerspace,^[6] or 3D printing marketplace. All of these avoid needing to purchase a personal 3D printer for printing off 3D models.

A dildo designed for anal insertion that then remains in place is usually referred to as a butt plug. A dildo intended for repeated anal penetration (thrusting) is typically referred to as an anal dildo or simply “dildo”. Anal dildos and butt plugs generally have a large base to avoid accidental complete insertion into the rectum, which may require medical removal. Some women use double-ended dildos, with different-sized shafts pointing in the same direction, for simultaneous vaginal and anal penetration, or for two partners to share a single dildo. In the latter case, the dildo acts as a sort of “see-saw”, where each partner takes an end and receives stimulation.

Some dildos are designed to be worn in a harness, sometimes called a strap-on harness or strap-on dildo, or to be worn inside the vagina (then called strapless dildo or “strapless strap-on dildo”^[7][8]), sometimes with externally-attached vibrating devices. Strap-on dildos may be double-ended, meant to be worn by users who want to experience vaginal or anal penetration while also penetrating a partner. They may also be used for anally penetrating men. If a female penetrates a male, the act is known as pegging.

Other types of dildos include those designed to be fitted to the face of one party, inflatable dildos, and dildos with suction cups attached to the base (sometimes referred to as a wall mount). Other types of harness mounts for dildos (besides strapping to the groin) include thigh mount, face mount, or furniture mounting straps.