Why Absolute URLs are Better than Relatve URLs for Blogs

[Halfdeck]

Does Google know this is the same site, or would this cause unwanted splitting of link power?

Her reason #1 applies to all websites; her reason #2 is a little more blog-specific, because spammers like to use RSS feeds to scrape blogs (one site scrapes and republishes everything I write, but by using absolute URLs every scrape turns into more one-way links for me).

I personally think a 301 redirect in htaccess is enough for Google to figure out canonical URLs, but using absolute URLs makes it crystal clear which version you prefer. For example, if a website has no 301 redirect installed from non-www to www and no Preferred Domain set in webmaster tools but all the internal links are absolute and links to the www version, link juice will flow to the right URLs through those absolute URLs.

For people who doesn't quite get canonicalization,

"www.domain.com/"
"domain.com"
"domain.com/"
"domain.com/index.html"
"domain.com/index.php"

are all unique URLs to Google. If you have backlinks to different versions, instead of having one strong page you got 5-6 weak pages. Though Google will get better at figuring out canonical URLs over time, I wouldn't leave it to Google to figure it all out just yet. All you gotta do is install a 301 redirect so that backlinks pointing at different versions consolidate into one URL.

Reasons why you should care:

- More PageRank means fewer supplemental results.
- Consolidated link juice can mean more ranking power.