Which is better for SEO an "UNDERSCORE" or "HYPHEN"?

[xuchunfeng1984]

by now, i think both of them are same in google. so you can use both of them for your website's url.

[aapus]

I dont know the exact theory but many so called "guru" out there claimed that hyphen is much more better than underscore.

[Jean-Luc]

Experts know that hyphens are better.

The problem with this forum is that newbies speak louder than experts.

Jean-Luc

[gareth_esutera]

Wikipedia is using underscores and their pages rank really well.

All other websites (that I know of) that uses Wiki as CMS use underscores.

On the other hand, websites powered by wordpress CMS are using hypens (at least, those with permalinks enabled).

Websites that are using either CMS tend to rank pretty well.

I'm using hypen but it's only because I'm using wordpress. For some unknown reason, underscore looks better for me.

[OroLatina]

Which is considered as a better approach for utilizing the keywords in the domain of the URL (for sub pages/internal pages of the site), a HYPHEN or an UNDERSCORE.

According to SEO standards practiced by Yahoo! and other SEO-heavy directories, the following applies:
Directories (collections of information) are best grouped and end with a / (with optional index page). For example, Latest Sports News or 14 Karat (14K) Tricolor Gold Pendants is a main page. Notice how a hyphen is used as a space character. This is commonly accepted in SEO terms and both Google and Yahoo! recognize it as such.
Internal pages are leaves off the branches above: A News Article or A Gemstone Pendant in 14 Karat (14K) Tricolor Gold ... This helps the search engine categorize the entries. Notice that the keywords are all lower-case in Yahoo? This helps with URL consistency, although Title Case is a good way to catch the eye with keywords.
Underscores, on the other hand, are usually reserved to delimit parts of URLs: examples include pagination and such: Page 2 of the Tricolor Gold Jewelry...
The SEO world is ever-changing, so none of this is set in stone... But I hope this post helps.

[nickoran]

Mr Cutts says Hyphen baby! YouTube - Should I use underscores or hyphens in URLs?

[nichita2008]

I seen a interview where Matt Cutts said that these days hyphens has the same value like underscore. I use always hyphens, but underscore can be used too. Are exactly the same thing in the Google's eyes.

[Doc]

I seen a interview where Matt Cutts said that these days hyphens has the same value like underscore. I use always hyphens, but underscore can be used too. Are exactly the same thing in the Google's eyes.

If you saw an interview where MC said hyphens are the same as underscores, I'd like to see a link to it. If you watched Matt's video, in Nickoran's post, he says just the opposite.

[Canonical]

Definitely hyphens. Many search engines (including Google) do NOT consider underscore a word separator. A couple years ago Matt Cutt announced that Google was considering implementinging code that would recognize underscore as a word separator, but recently he confirmed that more important projects prevented that change from ever being implemented.

If you go to youtube and search for "Should I use underscores or hyphens in URLs? matt cutts" you'll find the recent video from June where he explains "why" there is a lot of confusion around this issue.

[Doc]

Definitely hyphens. Many search engines (including Google) do NOT consider underscore a word separator. A couple years ago Matt Cutt announced that Google was considering implementinging code that would recognize underscore as a word separator, but recently he confirmed that more important projects prevented that change from ever being implemented.

If you go to youtube and search for "Should I use underscores or hyphens in URLs? matt cutts" you'll find the recent video from June where he explains "why" there is a lot of confusion around this issue.

Very true,Canonical. See post # 37 in this thread.