A nofollow link is a link that search engines will not follow and that doesn’t flow page rank. You can do this by using an attribute in the anchor text and that is “rel=nofollow”. When you place a comment on a website you have the ability to list your website address, your name, e-mail address (that usually is not published) and the comment itself.

By default the links posted in comments are nofollow links. My SEO tip for you is to leave it just like this. Changing those links in dofollow links could damage your website in terms of SEO. The reason is because search engines consider that you have total control of what’s being published on your website.