Proof Google Treats Underscores & Hyphens Differently?

Mar 23, 2009 • 7:10 am | comments (5) by twitter Google+ | Filed Under Google Search Engine Optimization

Over a year ago, almost two years ago, there were rumors that Google would treat underscores in the URL the same way they treat hyphens in the URL, as word separators. Matt Cutts squashed the rumor back then, suggesting that Google was not treating them the same.

Historically, underscores (i.e. was treated as a single word (i.e. filename) and hyphens (i.e. was treated as two words (i.e. file name).

A new WebmasterWorld thread asks more questions on that. Senior member, internetheaven, noticed, and I quote:

I have a URl:

and if you search for:

allinurl: file


allinurl: name

you get 0 results. Whereas if you search for:

allinurl: file_name

the page shows up in the results fine.

I thought underscores were the same as hyphens these days?

Well, they are not the same these days, and that might be proof. Technically, I do see results that do match on sites I tested for these types of queries. What I mean is that Google will still highlight and display results for a keyword that is in part of the underscored URL. I am not sure why it did not show up for this member. Maybe it is something happening at and since I am currently in Israel, I am getting a different data set.

Receptional, WebmasterWorld moderator, explained:

In certain cases, Google may figure out that underscore is being used as a word separator (similar to the process for conjoined words). But an underscore is not a word separator - treating it as such would at a minimum cause a lot of developers to be frustrated when using Google, as many function names etc. use underscores.

Underscores and hyphens have never been treated the same - if you want a guaranteed word separator in a URL, always use a hyphen.

For now, until we hear from Matt on a change in underscores and hyphens, Google treats them differently.

Forum discussion at WebmasterWorld.

Previous story: iGoogle Signing You Out?



03/23/2009 12:57 pm

This has always been one of the most retarded things Google has ever done. They feel as if computer nerds who search Google for programming functions will be too dumb to use quotes in their searching. Whereas they think everyone else will not be dumb when search for hyphenates. The fact is, grammatically, hyphens have a specific use. There are words in language (and especially proper names) that contain hyphens that are not word separators. There is no such case to be made for underscores. Underscores have no role in written language. They are the far more appropriate word separator for this function, and in fact have long been the traditional word separator in computing environments where spaces would be not allowed. If you were to search for McCain-Feingold Act you'd be searching for something very specific where that hyphen is supposed to be there. The bottom line is, Google doing this results in inconsistency. Suppose you wanted to write "Catherine Zeta-Jones" without a space. In Google's system you'd write "Catherine-Zeta-Jones" and you wouldn't be able to tell if Zeta is her middle name or if she has a hyphenate last name. In practically every other computing system you'd write "Catherine_Zeta-Jones" and the hyphenate would be obvious. But I guess Google figures that computer programmers searching for specific functions are too stupid to know to put quotes around searches containing special characters and so wants to sacrifice grammatically correct searching for all other searches because of it.

Jim DeSantis

03/25/2009 05:26 pm

Now I wonder if underscore spaced keywords in Meta work better than blank spaces or hyphenated? ie, internet_marketing, internet marketing, internet-marketing.

No Name

03/26/2009 04:53 pm

I agree with Chris, under scores are not used for anything, they should be more appropriate to use as separators. Underscores and hyphens should be treated the other way around.


04/24/2009 11:34 pm

I wonder how this applies to organic search. Seems unrelated but similar sounding sites with hyphens or underscores can get preference over normally written sites.


07/13/2009 10:51 am

Meta data is not affected. The keywords and descriptions are comma separated so the content which is grammatically correct with spaces, is treated as such.

blog comments powered by Disqus