What Is the Difference Between URL with and Without Www? Explanation of The Need to Unify and How to Set It Up

www Difference

Many people may think that the URL of the site always has “www”. However, if you look closely, there are also sites that do not have “www”.

What’s the difference between a site with “www” and one without?

This time, we will explain the difference between with and without “www”, problems when overlapping, and countermeasures and setting methods.
I hope that you will deepen your understanding of the “www” of the site URL that you are not usually aware of.

What is www?

If you look at the URL of the site, I think that it is often written as “www” at the beginning. This “www” is an abbreviation of “World Wide Web”, and it constitutes an address on the Internet in combination with the domain following “www”.

“www” represents the host name and specifies the server to connect to. A server is a computer that stores data and sends data to users over a network.

All data about the sites you visit is stored on our servers. A user requests data stored on the server by entering the URL of the site. The server provides the requested data to the user, and the user receives the provided data through the browser. This is how you can browse the site.

There are countless servers that store data, and users must identify the server that stores the data they want to view. At this time, the URL that is used to identify the server is the combination of the host name of ‘www’ and the domain such as ‘.co.jp’ and ‘.com’.

In fact, it is possible to browse the site by entering the number corresponding to the address on the Internet called “IP address”. However, this is a string of numbers and is difficult to remember, so the combination of “host name + domain” is the mainstream.

Impact on SEO with or without www

As mentioned above, “www” represents the host name, but you will notice that some sites do not have “www”.

In fact, it doesn’t matter if the site URL has “www” or not, both will access the same site, and there is no impact on SEO. However, from an SEO point of view, it is necessary to standardize on the presence or absence of “www”.

The reason for this will be explained in the next chapter.

One of the advantages of having “www” is that you can tell at a glance that it is the URL of the site. It means that “www” is pervasive. Also, having “www” on the corporate site will give users a safer image.

The advantage without “www” is that the URL is short and easy for users to remember.

Nowadays, smartphones are more important than PCs when it comes to viewing sites, so the shorter the URL, the easier it is to enter on a smartphone, so it can be said that it is more convenient for users to use without “www”.

Both with and without “www” have their merits, so you can freely decide which one to choose.

Read Also: What is “direct” in Google Analytics?

Reasons why you should unify the presence and absence of www

I mentioned that there is no difference with or without “www”, but there is one thing you should be aware of as an SEO measure. That is, if you currently operate a single site with both domains with and without “www”, you should immediately unify to one or the other.

If you run a site with both a domain and a domain without it, search engines will perceive it as two separate sites. As a result, the evaluation from the search engine will be scattered, and the SEO effect will be low.

At worst, two sites may be flagged as duplicate content and penalized.

There is no problem with or without “www”, but from the viewpoint of SEO measures, avoid running one site on two domains and run it on one domain.

3 patterns of setting methods with and without www

There are 3 patterns of setting methods to unify the presence or absence of “www”: “301 redirect method”, “canonical tag method”, and “Google Search Console method”.

I will introduce each method, so if you need to set “www” from now on, please choose the method that suits you.

How to make a 301 redirect

301 redirect is a mechanism used during domain migration, and is automatically redirected to a unified domain by describing it in the “.htaccess” file that makes up the site.

One of the advantages of using 301 redirects is that the information on the source site can be transferred to the destination site, so it can be divided with or without “www” without lowering the evaluation of the original site. The point is that the two sites can be merged.

Since 301 redirect is a domain transfer method recommended by search engines, it can be seen that it is one of the effective methods for integrating two sites with and without “www”. .

To unify two sites using 301 redirect, it is possible by describing the settings in “.htaccess”, which is the file that controls the web server.

If you want to unify with “www”, write the following tag in the “.htaccess” file.

Rewrite Engine On

RewriteCond %{HTTP_HOST} ^sample\.com

RewriteRule ^(.*) http://www.sample.com/$1 [R=301,L]

If you want to unify without “www”, write the following tag in the “.htaccess” file in the same way.

Rewrite Engine On

RewriteCond %{HTTP_HOST} ^www\.sample\.com

RewriteRule ^(.*) http://sample.com/$1 [R=301,L]

Please upload a “.htaccess” file with these tags and make sure the redirect is working properly.

How to use canonical tags

There is also a method of using the canonical tag to unify the presence or absence of “www”.

If for some reason you can’t use the “.htaccess” file, it’s a good idea to use the canonical tag.

By using the canonical tag, you can tell search engines which page is the canonical URL to prioritize among the duplicate pages.

You can set it by entering a canonical tag in the <head> tag of the main page of the duplicate pages, or both of the duplicate pages. If you are using WordPress, there are some plugins for SEO that can be easily set up, so you may choose a plugin if necessary.

For the canonical tag to be entered in the <head> tag, copy the following and enter the site URL.

<link rel=”canonical” href=”https://sample.com/”>

The 301 redirect mentioned above automatically redirects to the site with the canonical URL when the site with the set URL is accessed, whereas the method using canonical tags leaves both duplicate sites. is to convey only the priority.

When using canonical tags, if you set the main URL site incorrectly, there is a risk that it will not be indexed and traffic will decrease, so be careful.

How to use Google Search Console

Another way to unify the presence and absence of “www” is to use Google Search Console.

By using “.htaccess” and “canonical” together with Google Search Console, it will be possible to unify the evaluation even if denormalized URLs are detected.

Google Search Console is an internet search analysis tool provided by Google. Mainly before the inflow of the site, you can clarify the problems you have on the search.

The URL unification method is as follows.

  • First, register two sites “with www” and “without www” in Google Search Console.
  • After logging in to Google Search Console, please register from “Add site” on the upper right of the screen.

After registration, just select the URL you want to unify as the domain to use on the “Use Domain” screen from the “Settings” of the site.

Precautions when setting www with/without

If “www” is duplicated, there are many negative aspects in terms of SEO, and in the worst case, you may be subject to a penalty. As mentioned above, there are several ways to unify the presence and absence of “www”, but there are some things you should be careful about.

If you make a mistake in each setting, the URL may not be indexed or the number of accesses may decrease drastically. There have been cases of lost search queries and backlinks.

It is important to design your site well in advance, as URL normalization involves a lot of risk. Think of canonicalization as something you’ll do later on when you discover that the site you’re using now has duplicate content.


There is no particular problem with or without “www”.

However, it is clear that there are many negative aspects in terms of SEO if the yes and no are not unified.

If the URL of your site is not unified, we recommend that you take action as soon as possible.

Also, if you are going to create a site from now on, please keep in mind a solid site design so that you do not have to change the settings later, which is risky and troublesome.