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CAPTCHA Types

Procaptcha’s default frictionless feature dynamically detects if the user is a bot or a human. If the user is likely to be a bot, the user will be presented with an image CAPTCHA challenge. If the user is likely to be a human, the user will not be presented with an image CAPTCHA challenge and will instead solve a simple, invisible Proof of Work (PoW) challenge.

Serve different types of CAPTCHA by setting the captchaType to frictionless, pow, image.

Set Type Implicitly

Section titled Set Type Implicitly
<div class="procaptcha" data-sitekey="your_site_key" data-captcha-type="frictionless"></div>

Set Type Explicitly

Section titled Set Type Explicitly
document.getElementById('procaptcha-script').addEventListener('load', function () {
    function onCaptchaVerified(output) {
        console.log('Captcha verified, output: ' + JSON.stringify(output))
    }
    // Get the Element using elementId
    const captchaContainer = document.getElementById('procaptcha-container')
    window.procaptcha.render(captchaContainer, {
        siteKey: 'YOUR_SITE_KEY',
        theme: 'dark',
        callback: onCaptchaVerified,
        captchaType: 'image', // `pow` or `frictionless`
    })
})

Proof of Work (PoW) CAPTCHA

Section titled Proof of Work (PoW) CAPTCHA

A Proof of Work (PoW) CAPTCHA challenge requires the user to solve a computational puzzle before submitting the form. It is easy for humans to solve but computationally expensive for bots.

prosopo procaptcha pow captcha challenge

The Proof of Work CAPTCHA type does not interrogate the user’s browser environment, use frictionless for that (above).

Image CAPTCHA

Section titled Image CAPTCHA

An image CAPTCHA challenge requires the user to select the correct image(s) that match the given prompt.

prosopo procaptcha image captcha challenge

The Image CAPTCHA type does not interrogate the user’s browser environment, use frictionless for that (above).