Adding "www" what are the implications

before the urls of the site didn't have wwww

[security56]

Hi, well I have change the url format of my site, so they will have "www" in them before I never use "www" on my links :) I didn't know much then, but now I decided to do so, to make my site more proffesional looking you could say.

I was wondering how will this affect my pr and indexing by google will I be penalize for doing so. and is there a way to do it so if I wont be penalize if this was to happen.

Thanks

[Wlauzon]

It should make no difference at all. Since URL's are translated into numbers anyway, the SE's should not care. But for a while you may get both showing up in SE results...

[otech]

It could have a huge difference if google has indexed all your existing URLs without the www.

This is the very essence of the canonical issue - Google, if it has indexed your site without the www in front, will see the changed links as pointing to different pages - this may cause duplicate content issues if it already has that page under another url (ie without the www) in its index (as mentioned in many posts on this website).

doing site:yoursite.com

does this produce results with www in front or not?

Do other people from other sites link to your pages with or without the www?

Pick the majority and stick with it, setting up 301 redirects from old non-www pages to the new ones at the very least.

[spiral]

From my experience the best and easiest way to avoid problems is to stick to one version (with or without www, it does not matter) and make general 301 redirection from one domain to another.
If you like your site with www, then redirection should be for all URLs without www to the same pages with www.
It can we made by configuring your web server or by server side include file - both depending on your web server type.

[trinorthlighting]

I agree, I had the issue where both were listed. I decided to use the www, checked all my pages links for non www and fixed the few that needed to be fixed. I did some quick 301 redirects and submitted my site map via google site map. All of my non-www's are now fixed.

[g1smd]

There is two lines of code that you can add to the .htaccess file that ensures that any and every request for a non-www URL is redirected to the equivalent www version of that URL. You should use that code. It solves a lot of problems and needs no future maintenance.

[Marval]

While I agree that the htaccess method is good and personal experience shows it works well with Google, I would also recommend checking (assuming you are using an Apache/Nix installation) for the server config Servername statement and verify it is set to www.domain.com and not domain.com - If it is the latter, any time you have a directory link, i.e. href="/newdir"
apache sees that it is a directory, issues a 301 redirect with the ServerName which would be a backdoor for Googlebot to find dupes (this is an issue I tried to bring up to googleguy some time ago when the canonical issue came about with their issue of the new bot software they use back in 2004 but I believe it got passed on to the engineers and then kinda got ignored)

[LunaC]

"I would also recommend checking (assuming you are using an Apache/Nix installation) for the server config Servername statement and verify it is set to www.domain.com and not domain.com"

Hmm, this sounds like it may be my problem. Could you please tell me how exactly would I check that?