You can follow these 2 Methods for redirect wordpress website from http to www

Method: 1 For Any Website

Step: 1 Go to Cpanel and Click on setting

Step: 2 Now enable Checkbox of hidden files

Step: 3 Refresh your Cpanel and go inside public_html here you see .htcess files you jst replace all available code to below code

 

                            RewriteEngine On

                           RewriteCond %{HTTP_HOST} !^www\. [NC]

                           RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]

 

Step: 4   If you don’t have .htaccess files then create a file name with  .htaccess

        and paste above code and save them

 

Step: 3 Now Refresh Your Website.

                  That’ It.

 

Method: 2 For Any WordPress Website

Step: 1  Go to Settting

Step: 2  General Setting Here You see

             WordPress Address (URL) and Site Address (URL) change http:// to http://www and update                       them

Step: 3 Now Refresh Your Website.

                  That’ It.

Basant Mallick