Customer can register at checkout with a 8 character password

By default, WooCommerce requires a level 3 password. You can down grade this to level 2 with this code:
add_filter( 'woocommerce_min_password_strength', create_function( '', 'return 2;' ) );
The code goes in functions.php for your child theme or you can use the “My Custom Functions” plugin.

Please explain the second point again.

Hi,
On checkout page the account password should not be more than 8 characters only.
The code which you have given will work not be more than 8 characters
add_filter( ‘woocommerce_min_password_strength’, create_function( ”, ‘return 2;’ ) );

I don’t think it works just on password length. That’s just one factor. The code is looking at other things, like whether the password has a number, a capital or a special character. It then calculates whether the password is strong / medium / weak.

The possible values in the function are:
3 strong = default
2 medium
1 weak or anything

There are some password plugins around that you can try. They may give you more control.

Actually i need total 8 characters password which included number, letter and special character. In 8 characters i need strong, medium, weak password.

Your choices are only password strength settings of 3 (default), 2 or 1. Using just WooCommerce functions, you cannot specify the password more than that.

A level 2 password might be only 7 characters, or more than 8 if its a simple password.

For more control, have a look for password plugins at www.ads-software.com/plugins and codecanyon.net

Can i restrict password strength setting to 8 character only. can you share a code to me.
example if user type password less than 8 character it should give error (please enter maximum 8 character) and also if user type password more than 10 character it should give error (please enter maximum 8 character) only.

Sorry, no. Its unlikely someone would do that code development by way of a forum answer. Have a look for a password plugin, otherwise you may need to get a developer.