Last updated: 12 July 2025

Click fraud costs advertisers billions each year. While captchas like Google’s reCAPTCHA and Intuition Machines’ hCaptcha are widely used to stop bots, they fail to protect you from click fraud. Here’s why - and what really works.

What is a captcha?

Captchas are challenges designed to tell humans and bots apart by asking visitors to solve puzzles or click buttons. Once completed, the visitor can proceed.

What is click fraud?

Click fraud is a $100 billion scam where criminals create websites, place ads, and use bots to click those ads, draining advertisers’ budgets. The ad networks earn revenue on each click, creating a conflict of interest that leads to weak click fraud prevention.

You can read more about click fraud here: What is click fraud?

Why common captchas don’t stop click fraud

There are plugins which allow bots to bypass reCAPTCHA and hCAPTCHA.

For example, the bot framework Puppeteer Extra includes a plugin (puppeteer-extra-plugin-recaptcha) that solve reCAPTCHAs and hCaptchas automatically with a single line of code: await page.solveRecaptchas().

How Polygraph captchas are different

Unlike common captchas, Polygraph’s captcha system is specifically designed to stop click fraud bots from completing fake conversions-such as submitting fake lead forms or adding items to shopping carts. This is critical because fake conversions train ad networks to send more bot traffic.

By blocking these fake conversions at the source, Polygraph not only disables bots but also helps “retrain” ad networks to recognize and avoid fraudulent traffic over time.

How to effectively prevent click fraud

To protect your campaigns, simply relying on common captchas is not enough. Instead:

  • Use search networks only; disable display networks and search partners where bots are most active.
  • Employ exact match keywords and extensive negative search terms to avoid bot searches.
  • Apply strict location targeting, using “located in” rather than “interested in” options.
  • Target known audiences and exclude “unknown” demographics.
  • Use a reliable click fraud detection and fake lead prevention service like Polygraph to identify bots and reduce wasted spend.

In summary

Common captchas like reCAPTCHA and hCaptcha are no match for sophisticated click fraud bots that can bypass them automatically. Polygraph’s specialized captcha and detection tools stop bots before they can complete fake conversions, helping to protect your ad budget and retrain ad networks to reduce fraudulent traffic long term.