I am not an SEO guru, but I did read a book on it once… OK, a couple of books.

So I learned something new today, about dashes versus underscores and SEO.  You should use dashes rather than underscores in your webpage names.  Why?  Because Google will parse a dash as a space, thus separating words you want separate. But an underscore remains an underscore, which means people would have to search for the words with an underscore between them.

Example: Let’s say you’re selling icons.  And you have some Vista and XP icons for sale.  You’d like to do everything you can for Google to place your website highly for the phrase “Vista icons”.  So you name one of your webpages vistaicons.html.  Bad idea.  People don’t search for “vistaicons”, they search for “vista icons” (note the space).

OK, fine.  So you name your webpage vista_icons.html.  Still a bad idea, because Google doesn’t translate the underscore to a space.  It thinks when you have an underscore, you mean an underscore.  Which means people would have to be searching for “vista_icons” for this one to work.

Why do underscores stay as underscores, instead of being translated as a space (which is what you wanted, right)?  Because Google was written by computer nerds, and in the computer nerd world, underscores are important characters.  If Mr. Nerd is searching for a technical term that has an underscore in it, he will not appreciate Google turning the underscore into a space.  To a hardcore computer nerd (and we know Google has a few of those on staff), an underscore is an underscore, thank you very much.  It is not a space.  Kinda like the letter “a” is the letter “a”, not the letter “b”.

So if you want Google (and presumably, other search engines) to parse your webpage name into separate words, and hopefully give you a little SEO boost for those words (assuming they exist in your webpage as well), then use a dash between the words.  Thus, for our example, the best webpage name would be vista-icons.html.

Many thanks to Dave Collins of Software Promotions for this tidbit, shared in the excellent website critique webcast he did today.

7 Responses to “Dashes vs. Underscores in webpage names”

  • Rosemary says:

    Thanks for the great tip. This explains a lot of about some of the search results we find on Google!

  • Scott Kane says:

    It is a good tip. I do my pages and blog posts that way by default. I’ve noticed the difference in results, but it’s one of those things, for some reason, I never wondered exactly why about. Until now that is. :-)

  • Mike says:

    Read here for a totally different opininion based on real experiments:


  • SurlyE says:

    I read Mike’s post on his blog and experimented using his advice and found exactly the opposite to be true. If I searched word combinations / possible web page names with just spaces the search returned only pages like example: > Members-Form.html and it was not until I purposely searched Members_Form that I viewed any listing of example: > Members_Form.html. My Findings so heavily favored the above article that it is nonsensical to even debate.


  • Ben Arlo says:


    I’m wondering what the story is with website titles. If I use a dash in the title (not url) that an unreadable character comes up when I check my site on google.


  • Susan Alta says:

    Hi Ben, That shouldn’t happen. Dashes in titles should display as dashes or spaces in Google. You might make sure that you used the regular dash character (-) and not the elongated dash character (—).

  • Gorbo says:

    Excellent example, I have only one domain using dashes and is ranking ok for the main keyword.