The sonic screwdriver was a highly versatile tool used by many people throughout the universe, the most prominent of them being the Doctor. It was considered to be very advanced Gallifreyan technology, although the Doctor could make one by using resources found on 21st century Earth with help from Stenza technology. Other individuals had similar devices, such as a sonic trowel, sonic pen, sonic lipstick, sonic cane or a pair of sonic sunglasses.

From time to time, the sonic screwdriver needed to be recharged. It was self-repairing and could send out a homing signal to any parts that had been separated. Sonic screwdrivers and similar technology could not unlock a deadlock seal. Some or all versions were ineffective against wood.

Basic models of their sonic screwdriver were used mainly for the picking of locks and for projecting sound so as to, for example, detonate objects and fry circuitry. Once upgraded, it was able to also be used as a sophisticated scanning device, with medical applications. Subsequent incarnations gave it even wider functionality, such as the ability to hack into computers, provide geolocation and actively defend against some types of assault weapons by frying their internal mechanics and causing the weapons to burst into flames and spark from the inside. The tool could create powerful frequencies and signals, as well as use sound to carry out its functions, even to the point as shooting sonic energy waves to briefly incapacitate or stun a target. It could also cut and re-attaching materials such as barbed wire.

The newer model could create a holographic screen with adjustable dials to begin analysing data. It could also generating shields to stop bullets and neural anesthetic shots.