Accessibility links
reCAPTCHA and Duolingo: Luis von Ahn In 2000, Luis von Ahn was starting his PhD in computer science when he attended a talk and happened to learn about one of Yahoo's biggest problems: automated bots were signing up for millions of free Yahoo email accounts, and generating tons of spam. Luis' idea to solve this problem became CAPTCHA, the squiggly letters we type into a website to prove we're human. He gave away that idea for free, but years later, that same idea had evolved into a new way to monetize language learning on the web, and became Duolingo. Today, the popular app is valued at $1.5 billion, and is seeing a big spike in growth while people are confined to their homes.
Special Series

How I Built This

For all new episodes, go to the How I Built This page on Wondery.com Listen early and ad-free on Wondery+ Listen on Amazon Music

reCAPTCHA and Duolingo: Luis von Ahn

reCAPTCHA and Duolingo: Luis von Ahn

Listen ยท 1:06:02
  • Download
  • <iframe src="https://www.npr.org/player/embed/860884062/861156080" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
Enlarge this image

Luis von Ahn is the co-founder and CEO of Duolingo Maren Bruin for NPR hide caption

toggle caption
Maren Bruin for NPR

Luis von Ahn is the co-founder and CEO of Duolingo

Maren Bruin for NPR
How I Built This with Guy Raz

How I Built This with Guy Raz

In 2000, Luis von Ahn was starting his PhD in computer science when he attended a talk and happened to learn about one of Yahoo's biggest problems: automated bots were signing up for millions of free Yahoo email accounts, and generating tons of spam.

Luis' idea to solve this problem became CAPTCHA, the squiggly letters we type into a website to prove we're human. He gave away that idea for free, but years later, that same idea had evolved into a new way to monetize language learning on the web, and became Duolingo.

Today, the popular app is valued at $1.5 billion, and is seeing a big spike in growth while people are confined to their homes.