Availablelive test

hCaptcha

A checkbox that leads to "select all images containing..." grids. Positioned as the privacy-friendly reCAPTCHA replacement; Cloudflare used it for its own challenge pages from 2020 until Turnstile replaced it in 2022.

Vendor

Intuition Machines

Launched

2017

Type

Checkbox + image puzzle; invisible and passive modes on paid plans

Can I install it?

Yes, free publisher plan with a key from hcaptcha.com

Price

Free tier; Pro and Enterprise plans for passive mode and accuracy controls

Replace with

CleanTalk (invisible, checks the sender too) or Turnstile (browser check only)

Live widget

hCaptcha test key

Tick the box. The publisher test key never challenges and always returns the same test token.

Time it in the full test

What the visitor goes through

A checkbox, then often an image grid: "select all images containing a boat". Difficulty rises with suspicion and with the free plan, which serves challenges more aggressively than paid tiers.
Accessibility goes through a separate cookie-based opt-out that the visitor must set up in advance.

How it gets bypassed

Every solver service lists hCaptcha; image grids are solved by vision models or by people paid per thousand puzzles.
Image challenges in general take 15 to 26 seconds for humans with 71 to 85 percent accuracy, while bots solve them faster and more accurately (Searles et al., USENIX Security 2023).
Human spam passes untouched.

What it costs

Drop-off on challenge screens is reported at 5 to 15 percent depending on difficulty (industry figures cited in Cap's conversion guide). The checkbox alone is cheap; the grid is where the submissions go.

Embed code

The key below is hCaptcha's public test key; replace it with your own site key.

<script src="https://js.hcaptcha.com/1/api.js" async defer></script>
<form method="post">
  ...
  <div class="h-captcha" data-sitekey="10000000-ffff-ffff-ffff-000000000001"></div>
  <button type="submit">Send</button>
</form>
<!-- server: POST https://api.hcaptcha.com/siteverify with secret + h-captcha-response -->

No grids, no boats, no lost submissions

CleanTalk decides from the sender's reputation and behaviour, not from a picture quiz. The same form, zero clicks, spam still blocked.

1,105,000+ websites protectedup to 99.97% accuracylive in 60 seconds7-day free trial, no card

Start 7-day free trial Run the full test

Sources: docs.hcaptcha.com (integration testing: test keys; script and widget markup); Cloudflare blog on moving from hCaptcha to Turnstile (2022); Searles et al., USENIX Security 2023; Cap, "CAPTCHA Conversion Rate" guide. Related: reCAPTCHA v2, Turnstile. CleanTalk is not affiliated with Intuition Machines.