clock menu more-arrow no yes

Why captchas are getting harder

Want to watch this video? Please identify all the traffic lights first.

It’s not you — captchas really are getting harder. The worst thing is that you’re partly to blame.

A captcha is a simple test that intends to distinguish between humans and computers. While the test itself is simple, there’s a lot happening behind the scenes. The answers we give captchas end up being used to make AI smarter, thus ratcheting up the difficulty of future captcha tests.

After a failing a captcha, the test will provide you more images, giving you another chance to prove your humanity.
Is there any feeling more frustrating than clicking all the correct answers and getting a “please try again”?
Screenshot, Edward Vega

But captchas can be broken by hackers. The tests we’re most familiar with have already been broken. Captcha makers try to stay ahead of the curve but have to balance increasing the difficulty of the test with making sure any person — regardless of age, education, language, etc. — can still pass it. And eventually, they might have to phase out the test almost entirely.

You can find this video and all of Vox’s videos on YouTube. Subscribe to our channel to stay updated.


Correction, May 19: At 5:22 in the video, there is an incorrect statement on Google’s use of reCaptcha V2 data. While Google have used V2 tests to help improve Google Maps, according to an email from Waymo (Google’s self-driving car project), the company isn’t using this image data to train their autonomous cars. For more on the future of self-driving cars, check out this article from Vox’s Kelsey Piper.