Developer's Guide

Welcome to the developer documentation for reCAPTCHA API version 2.0! This guide applies to both new CAPTCHA installation and existing CAPTCHA upgrading.

ReCAPTCHA lets you embed a CAPTCHA in your web pages in order to protect them against spam and other types of automated abuse. Here, we explain how to add reCAPTCHA to your page.


This documentation is designed for people familiar with HTML forms and server-side processing. To install reCAPTCHA, you will probably need to edit some code.

We hope you find this documentation easy to follow. Make sure to join the reCAPTCHA developer forum to give feedback and discuss the API.


Adding reCAPTCHA to your site consists of three steps:

  1. Getting started
  2. Displaying the widget
  3. Verifying the user's response

Code Examples

The following are example code for various programming language and applications: