Why can’t computers complete CAPTCHAs? © iStock

Why can’t computers complete CAPTCHAs?

Common CAPTCHAs have been around since 1997, but computers are a long way behind the human brain at cracking them.

Asked by: James Malpas, Histon

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On a website’s login page, CAPTCHAs are those obscure-looking characters we use to verify that we are human users and not bots. The characters are often distorted with the letters or numbers running into each other. Optical character recognition software struggles to pick out the individual forms, especially when their shape and size vary from one CAPTCHA to the next.


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