Captcha Bank is a anti-spam captcha plugin for WordPress forms that adds secure image captcha or math captcha to prevent spam.
Demo : https://phpceil.com/contact/
简洁的中文验证码插件。在 WordPress 登陆、注册或评论表单中加入验证码,支持字母、数字、中文和算术形式。 Adds Captcha Code anti-spam methods to WordPress forms. Supports numbers, alphabets and Chine …
CAPTCHA Solution is a CAPTCHA module intended to be called from other plugins. It is originally created for my Contact Form 7 plugin.