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ChatGPT (2025) is dumber than Shrdlu (1970)
by David Lee
Captchas – might I be a robot after all?
22.6.2024
Translation: Eva Francis
Does this corner count as a traffic light? Is that an «I» or an «l»? If you’ve ever surfed the Internet, you’ll have asked yourself these and similar questions. Why? Because of captchas. What are these online puzzles all about, and why are some of them so difficult?
«I’m not a robot,» it says on the screen in front of me. I click the box and a picture puzzle appears. I’m asked to «Select all images with traffic lights». Well, does that mean only the traffic light as such or also the pole it’s attached to? And what about that tiny bit of the traffic light that covers about three pixels of the image in the top left-hand corner? Does that count?
Isn’t it ironic that we have to prove almost every day that we’re not robots – to robots! And what used to be photos and distorted letters are now AI-generated images of animals or actual puzzles that we’re asked to distinguish and solve.
But why are these captchas becoming harder an dharder? And isn’t there a better way of checking if someone’s a robot or not?
What’s a captcha?
You can probably already guess why this is needed online. The purpose of captchas is to protect websites from bot attacks. And at least in the past, picture puzzles and distorted letters were a relatively safe way to keep bots out.
But ten years ago, Google admitted in its own security blog that a lot of bots had learned to solve the captchas that were used at the time – with an accuracy of almost 100 per cent. So, a new solution was needed.
Man versus machine: a close race
So what do we do when every captcha puzzle or task can be solved by robots? Google’s answer? No more puzzles.
What robots can’t do
In most cases, that’s it and you’re in. However, if the probability isn’t high enough, you have to solve another puzzle to be on the safe side.
But captchas train AI, right?
Yes and no. There have been speculations for years that we’ve been teaching AI models what traffic lights, road signs and motorcycles are. Google has admitted in the past that the data from reCaptchas is used to improve OCR text recognition and Google Street View.
When the industry of self-driving cars got rolling, captchas with traffic lights started to appear. Relevant XKCD. But even if it seems likely that we’re training current AI models and teaching Teslas to drive with captchas, it’s never been confirmed.
So do I have to click on the traffic light pole or not?
Captchas have been an important part of the Internet since the early 2000s. A calculation from 2006 showed that 200 million captchas are solved every day. At 10 seconds per puzzle, that’s 150,000 hours, or over 17 years (!) of solving puzzles per day. Now imagine what this number looks like today.
However, with new developments such as Google’s reCaptcha, you should have to solve fewer and fewer captchas in the future. On top of this, technologies are already being developed that could potentially make captchas completely obsolete.
Until then, the answer’s no. No, you don’t need to click on the traffic light pole.
Captchas usually aren’t too strict with your image selection. If you have some spare time and want to brush up on your captcha skills, here are the most common ones to try out.
Dayan Pfammatter
Freelance Editor
pf.dayan@gmail.comI've been fascinated by all things keys, displays and speakers for basically as long as I can remember. As a journalist specialising in technology and society, I strive to create order in the jungle of tech jargon and confusing spec sheets.
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