The world's most transformative technology began with a crash.

The First Message on the Internet Was a Crash

ARPANET sends its first transmission between two computers — and fails gloriously

On October 29, 1969, the first message was sent over ARPANET — the internet's predecessor — but the system crashed after just two letters: 'lo.'

At 10:30 PM on October 29, 1969, a graduate student named Charley Kline at UCLA typed the word "login" into a computer terminal, attempting to send it to a computer 350 miles away at Stanford Research Institute. This was the first message ever sent over ARPANET — the predecessor to the internet.

The system crashed after the first two letters. The first message ever sent over the internet was "lo." (A year and a half later, when Kline was interviewed, he joked: "What could be more poetic?"

ARPANET was funded by the U.S. Defense Department's Advanced Research Projects Agency, which wanted a communications network that could survive nuclear attack by routing around damaged nodes. The key innovation was "packet switching" — breaking data into discrete packets that could travel different routes and be reassembled at the destination — developed by Paul Baran and Donald Davies independently.

The network grew slowly: four nodes by the end of 1969, 15 nodes by 1971, 23 by 1972. Email was added in 1971 and quickly became the network's most popular application. The modern internet's protocols, TCP/IP, were developed in the 1970s. ARPANET was decommissioned in 1990, by which time the intern…

💡 The first email was sent in 1971, and the sender can't remember what it said. He described it as 'something like QWERTYUIOP.'