What Should Be Preferred in URLs – Dash or Underscore?

The struggle of improving URL structure never ends, as discoveries and findings are made that negate the previous standards. The use of dashes and underscores in web addresses has always been a controversial topic, until Google recommended the hyphens over underscores in guidelines.

The content guideline states that

“The URL is much more useful to us than We recommend that you use hyphens (-) instead of underscores (_) in your URLs.”

In light of the above statement, most of the developers and marketers consider the issue resolved, whereas most of the programmers are still comfortable with the use of underscores. It might be that Google is more inclined to consider the ease of a layman rather than programmers that the dashes (-) are the preferred word separators in the URLs. The following are some of the justifications in support of what Google has finalized, as they have not given any explanation for it.


The recent advancement in technology is revolving around a common man. Generally, people are more familiar with a hyphen (or dash) than an underscore. So, if you want the customers to easily type the URL in the future, then the preferred link structure can be rather than It can be regarded as a friendly URL. As you can see, a layman cannot recognize the underscore used in the second URL. All the shopping carts have a friendly urlstrtucure e.g. Magetno, Opencart. At the same time, some other shopping carts don’t have such structure e.g. PrestaShop where PrestaShop SEO friendly URL module is used to make it more user and search engine friendly.

The hyphen sign is also suggested because of its regular use in our written language, whereas underscore is a purely computer related sign. Users can easily type a minus sign between the words and reach you rather than pressing it with a combination of the shift button.


To enhance the readability of a user, word separators are used in the URLs. A keyword or phrase that is added to a link without any space is hard to read. For example, is quite ambiguous. If you need to separate the words, you can write it ‘baby garments’ and the URL will appear as Though it splits the phrase, but compromises the readability of your web address.

Here again, you can compare the use of a dash, i.e. which is more appealing, precise and easy to remember.

The readability of a URL is also tested for search engine robots. As the Google treats the dashes as word separators, the underscores are known as word joiners. For example, /toddlers_shoes/ is crawled as /toddlersshoes/, which is not a threat to search engine visibility but not recommended by marketers.

With the Aspects of SEO

As far as SEO is concerned, previously the marketers found that Google may penalize the URL for the use of hyphens, which is not explicitly denied, as Matt Cutts – a senior software engineer working in Google – declared it in a post. You can read it in detail.

So, there is nothing harmful in using the dashes in the URLs. In fact, these are preferred over underscores, and that both these special characters are dealt with separately. Most of the marketers recommend the use of dashes for effectively optimizing URLs.

According to the above discussion, for an underscore, the search bot may show in the SERPs for a related query like ‘baby_garments’ or ‘babygarments,’ whereas for a hyphen, it ranks against the keywords including the ‘baby’, ‘garments’, and ‘baby garments’.

How the Debate Started and Came to an End?

Matt Cutts, who is a renowned software engineer at Google and considered an authentic source for about algorithmic changes and how the robots scan URLs. The debate started back in 2007 when he left an improper comment which promoted the perception among marketers, bloggers, and affiliates that underscores are considered as word separators.

Soon after the misconception, Matt rectified the whole thing in his blog and denied the fact that he has equated underscores with hyphens. It further stated that there is no need to switch domains to hyphenated URLs, whereas beginners shall start using hyphens as preferred word separators.

Following the same concept, he confirmed it in 2009 and 2010 in a video ( It clearly indicated that underscores are not among the word separators, and these can be replaced with hyphens for higher search engine visibility.

Finally, the debate concluded with Matt’s new video in 2011, which confirmed that hyphens play a vital role in structuring URLs for SEO, and that is true for a foreseeable future or until a major change occurs in search engine algorithms.


After going through the release of authentic information, there is no point inpicking underscore over hyphens,relying on self-projected ideas and perceptions. Any logic for readability and familiarity seems to be void when there is a definite answer from the industry experts.

Matt concluded that there is a difference of ranking between the two, which may be negligible for some experts, but it exists. And, that users, who have already established their businesses over the URLs that include underscores do not have to worry, because with 301 redirects that can avail the same link juice along with all the benefits associated with hyphenated URLs.

Author Bio

Alastair Brian writer from “FMEModules” – a brand well known for top of the line reliable PrestaShop Add-ons, themes, extensions and services. Follow him on TwitterLinkedIn.