Why does the world have 15 plug types?

Humanity has agreed on many things. The metre. The second. That pineapple on pizza is worth arguing about. But when it came to the shape of the holes in our walls, we threw up our hands and said "you do you."

It started in America

The first plugs weren't plugs at all. Early electric appliances screwed into light bulb sockets, because that's where the electricity was. In 1904, an American inventor named Harvey Hubbell patented a separable plug, and soon after came the two flat blades that would become Type A.

Then everyone else got electricity

Here's the problem: electrification happened country by country, over about 60 years, with no international coordination. Each country picked whatever its engineers liked, and once millions of walls had those sockets, changing them became effectively impossible.

• Germany came up with the Schuko (Type F) in the 1920s: symmetrical, grounded via side clips, and reversible.
• France put a ground pin in the socket instead of the plug (Type E), because of course it did.
• Britain rebuilt after WWII with a new fused plug (Type G), partly because copper was scarce and ring circuits saved wire. The fuse in each plug made it safe.
• Switzerland, Italy, Denmark and Israel all went their own way too.

The Europlug: a peace treaty

In the 1960s, Europe noticed it had a problem and invented the Europlug (Type C): two thin round pins, no ground, low current. It was designed to fit almost every socket on the continent. It's the closest thing the world has to a universal plug, and it's why Plugbert's top tip for most of Europe is "bring a Type C."

The last attempt

In 1986 the IEC designed a genuinely universal plug, IEC 60906-1. Literally one country adopted it: Brazil, in 2011, as Type N. South Africa adopted a close cousin. Everyone else said "maybe later."

So here we are. Fifteen types. A to O. Plugbert has met all of them, and he'd like you to know that Type G is lovely once you get to know it, but you should never, ever step on one.

Browse them all on the plug types page.