Technology
How do CAPTCHAs work?
A CAPTCHA works by posing a challenge that's easy for humans but hard for bots — like reading distorted text or picking images. Newer versions quietly analyze your behavior, such as mouse movements, to tell humans and automated scripts apart.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how CAPTCHAs works.
Step by step
- 1They pose tasks easy for people but hard for bots.
- 2Classic ones use distorted text or image puzzles.
- 3Modern ones analyze behavior like mouse movement.
- 4They protect sites from spam and automated abuse.
Frequently asked questions
- How do CAPTCHAs work?
- They present challenges humans solve easily but bots struggle with, sometimes analyzing behavior invisibly.
- What does CAPTCHA stand for?
- Completely Automated Public Turing test to tell Computers and Humans Apart.
- Why do some CAPTCHAs just need a checkbox?
- They analyze signals like your mouse movement and history to judge you're human without a puzzle.