Absolute vs relative links for search engine crawlers and SEO

There's pros and cons to both implementations:

Absolute: Deters scrapers (since they will have to replace all base href values). Allows for better testing in production sites - not relying on missing folder heirachy etc. Less overhead for URL retrieval (debated).

Relative: Easier for development (on a staging server or local server etc) without the need of dynamic base href. Easier to transport or move the site to another (sub)domain/folder.

So while you can see there's no SEO value to be had on way or the other, one thing that is commonly agreed in SEO is that "Good URLs NEVER change", hence my (personal) preference for insisting on absolute URLs.

According to Google both work but they recommend full URLs. From Matt Cutts:

I recommend absolute links instead of relative links, because there's less chance for a spider (not just Google, but any spider) to get confused

Source: Googleguy (aka Matt Cutts) on WebmasterWorld.com (June 2, 2005)

Although, it depends upon the SE, for some, providing full absolute linking, would reduce the amount of processing required to index the website, but I am not sure if this method is still used currently.

However, providing absolute link, would help when the user wishes to save the content for offline reading, and then it would make it possible for him to browse back to online content from his saved offline page.