Silver has the highest electrical conductivity of any metal.
At room temperature, pure silver conducts electricity slightly better than copper, gold, or platinum. Its conductivity is linked to the way its outer electron can move through the metal’s crystal lattice with relatively little resistance. Silver is also an excellent conductor of heat and has very high optical reflectivity.
Copper is used far more widely in household wiring because it is much cheaper and lighter for many applications. Silver’s price and density make it uneconomical for most long cables, even though its electrical performance is superior. It is still valuable in specialised electronics, switches, contacts, radio-frequency components, printed circuits, and conductive pastes.
A common mix-up is to choose gold because gold is famous for electrical contacts. Gold is less conductive than silver and copper, but it resists oxidation and corrosion, so it remains reliable at contact surfaces. Platinum is also valued for chemical durability, not for having the best electrical conductivity. Silver can tarnish, yet tarnished silver can still conduct electricity effectively.