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The Internet & WebWeb Technology

Why 404?

The famous ‘Not Found’ number is not a room at CERN

You've met it a thousand times: 404, page not found. But why 404? Why not 12, or 9,000? Somebody chose that number. How?

You'll find out

  • The legend of the lost room at CERN
  • What a code's first digit tells you
  • The joke code that became permanent

Why it matters

Every page you open starts with one of these numbers. Its first digit tells you whether to fix, wait or move on.

About 3 min6 interactive slides · 5 questionsLesson 141 · Zone 16

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