What HTTP redirection method should I use?

I have a blog with a domain. And I'm buying another domain soon.

What I concerned is, when I change my blog domain, all links could be broken from other sites. I want the links alive forever, and also want it's page-rank not to go down.

For keeping my page-rank, what redirection should I use?(HTTP 301? 302? 303?)

I don't understand what their differe开发者_JS百科nce is.

The older domain is still mine.

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I'd say an HTTP 301 (Moved Permanently) redirect is your best bet.

It indicates a permanent redirect, which appears to be accurate in your case. It also prevents you from being imposed any penalties for duplicate content.

Any time a request is made to your old URL, the 301 redirect tells the search engine that the page has moved to a new location and provides it with the new, correct URL. Think of it like putting in a change of address request for your mail when you've moved to a new address.

EDIT: Google explicitly recommends using a 301 redirect when you've moved your website to a new address. From their page entitled "Moving your site" on Webmaster Central (emphasis added):

Use a 301 Redirect to permanently redirect all pages on your old site to your new site. This tells search engines and users that your site has permanently moved. We recommend that you move and redirect a section or directory first, and then test to make sure that your redirects are working correctly before moving all your content.

Don't do a single redirect directing all traffic from your old site to your new home page. This will avoid 404 errors, but it's not a good user experience. It's more work, but a page-to-page redirect will help preserve your site's ranking in Google while providing a consistent and transparent experience for your users. If there won't be a 1:1 match between pages on your old site and your new site (recommended), try to make sure that every page on your old site is at least redirected to a new page with similar content.

The second snippet of bolded text indicates to me that it's very likely you can maintain most of your site's ranking in Google's search results if you use a 301 redirect. I assume that temporary fluctuations in your rankings are possible, even likely, but as long as everything is redirected properly, there appears to be evidence that at least not all hope is lost. Some fluctuation or loss in PageRank is not the same thing as starting all over from scratch, as one of the comments indicates.

Google also advises letting them know when your site has moved, which may be worth doing—it looks like my "change of address" simile is even more precise than I thought!

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301 is "Moved Permanently":

http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

Casually searching for "301 pagerank" on Google results in many people claiming that 301 is the way to go.