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:
- Choose the client-side integration:
- Verify the user's response
.
Comparison of features between reCAPTCHA v3 and reCAPTCHA v2
The following table shows a comparison of the features in reCAPTCHA v3 and
reCAPTCHA v2.
Feature
|
reCAPTCHA v3
|
reCAPTCHA v2
|
Cost
For more information, see
Pricing
.
|
Free up to 1 million assessments per month
*
|
Free up to 1 million assessments per month
*
|
"I'm not a robot" widget support
|
No
|
Yes
|
Score granularity (security-review required)
|
4 levels
|
None
|