The sign sat in merchants' ledgers 500 years before it sat in email addresses. In 16th-century Venetian trade documents, a looped “a” abbreviated arroba — a unit of weight — and the shape stuck around through centuries of commercial shorthand meaning “at the rate of”.
The 1971 hack that made it immortal
Ray Tomlinson needed a separator for the first network email that could never appear in a person's name. @ sat on every Model 33 Teletype, meant roughly “located at”, and nobody used it for anything important. user@host was a keyboard convenience that became the identity layer of the internet — then of social media handles a generation later.
Why the key still moves countries
US keyboards put @ on Shift + 2; UK keyboards put " there and hide @ on Shift + '. Switch layouts by accident and the key “breaks” — our most-visited fix page walks through the ten-second diagnosis. For the shortcut itself on every platform, see how to type @.
The takeaway
@ survived because it was boring and available — the two most underrated properties in infrastructure. Every “© vs (c)” autocorrect and every moved key on this site has the same moral: characters are standards first, shapes second. Cite the standard (ours is documented here) and the shape follows.