Site Performance: rel=canonical vs redirect 301

问题

From this page on the blog of Matt Cutts, he says that rel=canonical should be a secondary choice if you can't use a 301 redirect. Is there any performance issue with using a 301 redirect instead of a rel=canonical?

回答1:

In my experience, the performance difference is negligible. There are more steps involved in the implementation of 301 redirects, so rel=canonical might perform slightly better. The extra steps are typically executed very quickly and should not add any noticeable delay or strain on server resources.

rel=canonical

1. User makes a request for /non-canonical.html
2. Server looks up canonical URL: /canonical.html
3. Server builds a page that includes the canonical tag and sends it to the user

301 Redirect

1. User makes a request for /non-canonical.html
2. Server looks up canonical URL: /canonical.html
3. Server issues a 301 redirect to the canonical URL.
4. User's browser automatically makes a second request for /canonical.html
5. Server discovers that this request is for a canonical URL.
6. Server builds a page and sends it to the user.

来源：https://stackoverflow.com/questions/15916949/site-performance-rel-canonical-vs-redirect-301