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Regarding bit.ly, from their FAQ: _bitly works by issuing a "301 redirect": a technique for making a webpage available under many URLs. When you shorten a link with bitly, you are redirecting a click from bitly to the destination URL. A 301 redirect is the most efficient and search engine-friendly method for webpage redirection, and is what bitly uses. Because bitly doesn’t re-use or modify links, we consider our redirects to be permanent._So you're fine there. Re your own short links, you'll have to check whether they are redirecting or using cannonical tags.