Magento 2 supports administrators to set CAPTCHA requirement for each time customers log into their accounts. The website is enabled to avoid spam and the Robots login to website. Thus, this feature will increase effectively your store security. To protect your store, you should enable Admin login Captcha and install Security module.
In the backend, you can configure whether customers are required to enter a CAPTCHA each time they log into website, or after several unsuccessful attempts to log in. Moreover, admins can configure to show CAPTCHA requirement for the following forms in the storefront
Stores. In the
Customersin the panel on the left
CAPTCHAsection, and continue with following:
Enable CAPTCHA on Frontendfield, select “Yes” to enable CAPTCHA on Frontend
Fontfield, select the name of the Font to be used for the CAPTCHA symbols. The default is LinLibertine.
Forms field, select one of the following forms where CAPTCHA is to be used
Displaying Mode, choose one of the following
Number of Unsuccessful Attempts to Login field, enter the number of unsucessful attempts to login before captcha appears. If you enter Zero, the Captcha will be always available
CAPTCHA Timeout (minutes) field, enter the number of minutes before the CAPTCHA expires. When the CAPTCHA expires, the user must reload the page to generate a new CAPTCHA.
Number of Symbols field, enter the range number of symbols that CAPTCHA will be changed in, for example: 3-7. The maximum number of symbols is eight.
Symbols Used in CAPTCHA field, specify the symbols that can be used in the CAPTCHA. Set only letters (a-z and A-Z), or number (0-9) to enter into the box. No spaces or other characters are allowed and the similar symbors is not used in the default.
Case Sensitive field, select
Yes if you require that the user enter the upper-and lowercase characters exactly as shown
Ref: Magento 2 User Guide
It comes to the end of tutorial: How to Enable Customer Login / Register Captcha in Magento 2.
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