What do you think? It's better _ or - as separator?


http://news.com.com/8301-10784_3-9748779-7.html

Well, the fact that Google officially states that underscores are now considered as separator does not means it's the best one.

I personally keep hyphens because they once where the only one to be considered as separators, and thus are more likely to work for most bots and Search engines.

Then, it's as well a matter of language, an hyphen is a genuine word separator, where underscore are never used when writing.

So at first, bots behaviour was pretty logical, treating things like "super-seo" as two words and "dll_32" as a single symbol.

So IMHO for the most, it's the same, but it still could be better to keep hyphens for some SEs.
I don't think that if an SE would penalize too much hyphens in some URL, it would no be the case with underscores.

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When in doubt, I opt for whatever site visitors would find better. Frequently what Internet users prefer and what search engines rewards is (sensibly) the same. I find hyphens are easier to read and already part of the language; underscore separators are programmer symbol delimiters. So...

Exactely.

I always use an underscore _ because I made most of my site with frontpage and it used to replace spaces with underscores. Problems occured when I updated to a newer version of frontpage and it stopped putting in the underscore and so I saved lots of pages with spaces

Then I found out that the internet does no like spaces and replaces many of them with %20 or similar and so now I always use underscores instead of spaces, but I guess you can use either as long as you do not leave a space

Yes, underscores are decently understood by most SE's bots now, and it's been a while, so there is no problem with these.