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What’s the point in having “www” in a URL?

My present DNS configuration for my website's A record is as below

Name              Value
example.com       67.45.xx.xx
www.example.com   67.45.xx.xx

In above configuration user can open website either by example.com or by www.example.com.

One of my SEO team-member argues for single point access.
According to him search engine’s crawler see 2 different name with same content. It is not good and we should configure domain in such a way that if user open example.com then browser automatically get redirected to www.example.com.

Now I have 2 questions

  1. Does above argument is valid?
  2. If yes then what changes I need to do in my DNS?

2 Answers 2


You don't need to change DNS for this at all.. He is correct in his argument though. Google doesn't like the same content for multiple hosts. So pick which one you want to use

example.com or www.example.com and do a 301 redirect from the one you don't want to use to the one you want to use.

The 301 re-direct is done with your webserver not dns. The 301 tells google.. hey.. the site now lives here.. change your links to use this url now and not the old one if it has links to both of the hosts.

  • 1
    Note that both example.com and www.example.com should pull up your website. Despite what Google may or may not "like", users should be able to type either and get to your site (how you redirect and map things is your call, but if you break one or the other you're shooting yourself in the foot)
    – voretaq7
    Commented Aug 25, 2012 at 15:39
  • yes but google punishes domains that serve the same content under different subdomains
    – Mike
    Commented Aug 25, 2012 at 16:50
  • 1
    True, which is why they should implement the 301 redirect from one site name to the other, but remember that users punish domains that don't work when they type them in (and the UX folks probably have harsh words for people whose sites break just because you didn't type "www").
    – voretaq7
    Commented Aug 25, 2012 at 16:57

Use a CNAME record to redirect to the correct page

A record www.example.com :

Then a CNAME record

*.example.com : www.example.com

example.com : www.example.com

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