AWS WAF Captcha is now available for all customers. AWS WAF Captcha helps block unwanted bot traffic by requiring users to successfully complete challenges before their web request are allowed to reach AWS WAF protected resources. You can configure AWS WAF rules to require WAF Captcha challenges to be solved for specific resources that are frequently targeted by bots such as login, search, and form submissions. You can also require WAF Captcha challenges for suspicious requests based on the rate, attributes, or labels generated from AWS Managed Rules, such as AWS WAF Bot Control or the Amazon IP Reputation list. WAF Captcha challenges are simple for humans while remaining effective against bots. WAF Captcha includes an audio version and is designed to meet WCAG accessibility requirements.
Source:: Amazon AWS