WordPress title separator is dash (-) by default. This is one of the most popular separators amongst all websites. However, if you would like to change the default title separator, WordPress gives you a really useful filter to do so.

If you want to change the default WordPress title separator, all you have to do is to use document_title_separator hook. See example usage below:

<?php
  function kafka_document_title_separator( $sep ) {
    return "//";
  }
  add_filter( 'document_title_separator', 'kafka_document_title_separator', 10, 1 );

Add this code to your functions.php file and it should do the trick.

Please note that this tip only works if your site title is automatically generated.

If your theme doesn’t have title-tag support you may need to enable this manually.

(via metinsaylan.com)