How to avoid duplicate content when changing urls?

[hansem]

Hi, I'd like to change the way my site works. I have dynamic site with urls like: blabla.asp?id=..... etc.

I've come up with the idea to change these urls to something more readable, like: /blabla-page

I do want the other urls to work to make sure older external links still work.

How can I achieve this without getting a duplicate content penalty?

Thanks,
Marco

[Coop99]

Use a 302 rediredct from the dynamic url to the static url - this way google will recognize what you are trying to do. You should avoid a duplicate content penalty this way. The next large update should reflect mostly all of the changes.

If you would like to keep your dynamic pages up you will not loose the links pointing to those urls.

Keep in mind any sites that are linking to the dynamic pages will have to change the url they link to if you take down the dynamic urls after the redirects are updated and indexed fully.

[Sweet Cognac]

We did the same thing in Jan 05. Changed dynamic urls to static urls. Never did any redirects. Google had it figured out the next time he spidered, and we didn't lose any rankings or suffer a dup penalty. Once he respidered we actually gained rankings.

So it depends,
1. What you are comfortable doing?
2. How often do your pages get spidered?
3. Do you have specialized and unique content?
4. How much does Google love your pages right now?

Yes, and make sure all your navigation links are fixed. If Google finds even just one wrong, he'll leave.