Developer's Guide

  • Google reCAPTCHA helps protect your website from spam, abuse, and fraudulent activities with v3, v2, and Enterprise options.

  • To use reCAPTCHA, you'll need to sign up for an API key pair (site key and secret key) and integrate it into your website or mobile application.

  • reCAPTCHA offers different integration options including v3, v2 (checkbox, invisible), and Android, allowing you to choose the best fit for your needs.

  • This documentation is intended for developers familiar with HTML, server-side processing, or mobile application development and requires code edits for installation.

Google offers reCAPTCHA (v3 and v2) and reCAPTCHA Enterprise to help you protect your sites from fraudulent activities, spam, and abuse. To know more about the features of reCAPTCHA and reCAPTCHA Enterprise, see Comparison of features between reCAPTCHA versions.

This document provides an overview of Google reCAPTCHA v3 and v2. For information about reCAPTCHA Enterprise, see the reCAPTCHA Enterprise documentation.

To get started with reCAPTCHA Enterprise, you can use our Site Registration Tool. This tool will help you create a new reCAPTCHA Site Key, and if needed also create a new Google Cloud account.

Get Started

Audience

This documentation is designed for people familiar with HTML forms, server-side processing or mobile application development. To install reCAPTCHA, you might need to edit some code.

We hope you find this documentation easy to follow. You can ask a question about reCAPTCHA on Stack Overflow, using the tag recaptcha.

Overview

To start using reCAPTCHA, you need to sign up for an API key pair for your site. The key pair consists of a site key and secret key. The site key is used to invoke reCAPTCHA service on your site or mobile application. The secret key authorizes communication between your application backend and the reCAPTCHA server to verify the user's response. The secret key needs to be kept safe for security purposes.

First, choose the type of reCAPTCHA and then fill in authorized domains or package names. After you have accepted the terms of service, click Register to get new API key pair.

Now, perform the following steps to add reCAPTCHA to your site or mobile application:

  1. Choose the client-side integration:
  2. Verify the user's response.