The debate rages.

Some swear dashes in domain names send rankings soaring.

Some have an ongoing love affair with underscores.

Others are sure there is no difference.

While I agree you do get a bit of a bounce in Google if you do this right - it's only marginal.

Still let's end this debate once and for all and PROVE which is better. Using Google search results (SERPS) to test if Google treats dashes or underscores the same or differently.

The guinea pig multi-word search term I picked is "affordable search engine placement".

To set a benchmark I first cast the broadest net possible doing a search using

affordable search engine placement

Google returned this:

Searched the web for affordable search engine placement.
Results 1 - 10 of about 78,600

That says 78,600 pages were indexed by Google for ANY of those keywords.

Next I searched on the same phrase only this time I separated the words by dashes like this:

affordable-search-engine-placement

Google turned up these results:

Searched the web for affordable-search-engine-placement.
Results 1 - 10 of about 1,160.

As you can see our term with dashes gave considerably fewer results than the one without.

Then I searched on the same words separated by underscores:

affordable_search_engine_placement

For this one Google didn't find much:

Searched the web for affordable_search_engine_placement.
Results 1 - 4 of about 6.

Finally I searched for

"affordable search engine placement"

Note the quotes. Using quotes limits the search results to one specific phrase.

In this case Google returned:

Searched the web for "affordable search engine placement".
Results 1 - 10 of about 1,160.

If that looks familiar it's exactly the same number of pages as the keyword phrase with dashes returned.

Okay so what have we got?

The first search returns what you could say is a free for all of listings with any of the words in the keyword phrase. That's why there are so many search results.

Next the phrase with underscores produced negligible results. As in next to none.

While the keyword phrase with dashes and the exact phrase search turned up the same number of SERPs.

At this point you should be wondering "Why is that?"

Glad you asked. Even if you didn't let me explain.

The reason for this apparent match of search results is Google uses the dash to separate the words in the phrase. Programmers call this a "delimiter". In essence Google sees the dash as a separator between the words.

Yet Google obviously does NOT treat the underscore as a delimiter. To Google it's just another character. Which is proven by the search results. Since if Google treated the dash and underscore alike the number of SERPs returned for

affordable_search_engine_placement

or

affordable-search-engine-placement

would be identical. But as you saw they are not. Not even close.

So the answer as to which is better, dashes or underscores, is obvious now isn't it? You want to use dashes in your domain names, folder names, files names etc.

That's because using dashes to separate the words will give you the biggest Google impact - whatever that impact may be. Since Google can parse the different words. While underscores don't help one iota.

Look. This isn't theory or speculation. It's fact. And you can repeat the same searches with any keyword phrase you want and you'll get the same results.

Yet to keep this real don't expect some kind of massive boost from this dash trick. Sure it can help a tad as part of an over all optimization scheme. But whether or not you use dashes in a domain, folder or file name is not going to be what gets you top Google listings. Content and links are.

Still this study does settle the debate about dashes and underscores. Giving you yet another little thing you can do to rank well.



About the author:

John Gergye shares more ideas like this in his just updated
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