CAPTCHA

American  

[kap-chuh] / ˈkæp tʃə /

Or captcha

noun

Digital Technology.

1. an online test designed so that humans but not computers are able to pass it, used as a security measure and usually involving a visual-perception task.

   Site visitors must solve the “distorted text” CAPTCHA before posting comments.

2. a computer program that generates such tests.

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Etymology

Origin of CAPTCHA

First recorded in 2000–05; C(ompletely) A(utomated) P(ublic) T(uring) (Test to Tell) C(omputers and) H(umans) A(part); inspired by capture ( def. )

Example Sentences

That’s great, and I want that, but sometimes I want entertainment, style and originality too, and all of those things exist in this exciting, economical tale of a woman who can’t get past a CAPTCHA.

From Salon • Feb. 28, 2025

This is sort of like — it’s occurring to me that we basically designed a CAPTCHA.

From New York Times • Mar. 20, 2023

When you go to a website that would normally ask you to fill out a CAPTCHA, that site can ask your phone or computer if a human is using it.

From The Verge • Jun. 20, 2022

For instance, spammers used to send messages with all text in a photo because filter bots can’t read photos—this is the idea behind CAPTCHA.

From Slate • Apr. 10, 2019

Indeed, Luis von Ahn, one of the Carnegie Mellon University team that coined the term CAPTCHA, says he’s skeptical.

From Forbes • Oct. 28, 2013