Map a Different Domain Name to a WordPress Page or Post

I had a client who wanted to map a domain name (different than the site’s root) directly to a WordPress Page, and not show the WordPress URL.

For example, let’s say you had a WordPress blog with this Page:
http://myblog.com/my-first-post/

But let’s say you want the URL of that post to be http://airplanesarecool.com.

Of course, you could do a simple redirect, but that would result in http://myblog.com/my-first-post being shown as the URL in your browser, not the original domain name.

In this article, I’ll show you how to mask a WordPress page or post with a separate URL with a completely different domain name.  

Pointing Your Domains

I am assuming in this article that you own the domain name that you want to use (i.e., “airplanesarecool.com”), and that it is pointing to the root of your WordPress site, but here’s a quick overview of what that entails.

First, you’ll need to go to your DNS records (often, but not always, found at your domain name host), and point the A-record of your naked domain at your server’s IP address (which can be found at your web host). Some DNS providers give you the ability to point your naked domain using a CNAME to a domain name instead of an IP address. That is pretty cool because it means you don’t need to change this again if you change servers and your IP address changes. The Namecheap DNS will let you do this. Sadly, GoDaddy’s DNS doesn’t allow this.

Now the domain is pointing at your server’s IP address, but not at a specific directory. If you’re on cPanel, go to Addon Domains to assign the domain to a directory. On Gridpane, go to the site -> domains in the control panel and create an Alias domain.

Next is the actual domain mapping.

Update: The WordPress Plugin Way

Since I first wrote this blog post, several WordPress plugins have come out that do domain mapping without the need for writing code!

One such plugin is Multiple Domain Mapping on Single Site. I tried this and it works great! The only caveat is that it won’t map a domain with a subdirectory.

Another domain mapping plugin that works well is Domain Mapping System. It has a paid version that will map subdirectories. I’m using the paid version with subdirectory mapping on about.build.

Yet another plugin that does this is Page as a Subdomain, but I have not tried that one yet.

If you want to do the whole thing “by hand” (i.e., in .htaccess code), AND you’re on an Apache server, then keep reading. But even if you’re using a plugin, you should skip down to the SEO section below for more things you need to do.

My First Try Using .htaccess (Apache only)

Note, this technique will only work on Apache servers. It won’t work on NGINX. There might be a way to get it to work on OLS, but I was unable to. The technique below worked on GoDaddy Apache servers for me.

I a not a mod_rewrite expert, but I knew the answer lay there. After a lot of reading and tinkering, I came up with this code for my .htaccess file:

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^airplanesarecool\.com$ [NC]
RewriteRule ^(.*)$ http://myblog.com/my-first-post/ [NC,L]

This did do the redirect, but it did not mask the URL. That is, the WordPress URL was still showing up in the browser, not the desired domain name.

I Am The One That Masks

After more tinkering, I discovered that the original domain name was preserved only if I redirected to a file at the root level. It wouldn’t work for subdirectories (maybe one of you knows why?)

Armed with that knowledge, I changed my approach to redirect the URL to the raw “non-pretty” WordPress URL, which is basically index.html at the root level with a query string. Thus, I came up with this:

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^airplanesarecool\.com$ [NC]
RewriteRule ^(.*)$ index.php?page_id=180 [NC,QSA]
RewriteCond %{HTTP_HOST} ^www\.airplanesarecool\.com$ [NC]
RewriteRule ^(.*)$ index.php?page_id=2218 [NC,QSA]

This works! If you type in “airplanesarecool.com” in the browser, it will display the page at myblog.com/my-first-post, but keep your original URL! Great!!!

If you also need to map subdirectories, use this variation:

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^about\.build$ [NC]
RewriteRule !^. index.php?page_id=2 [NC,QSA]
RewriteCond %{HTTP_HOST} ^www\.about\.build$ [NC]
RewriteRule !^. index.php?page_id=2 [NC,QSA]

As I mentioned, you’ll need to point your domain name at your WordPress root directory. That is, point airplanesarecool.com to myblog.com.

Next, place the code above the WordPress code in your .htaccess file at the WordPress root. That is, put it above the line that says:

#BEGIN WordPress

In the fourth line, specify the ID of your WordPress Page or Post. You can find the ID by viewing your Page or Post in edit mode and looking at the URL. It’s in there.

How it Works

The first line simply turns on the redirecting engine, and the second sets the base directory.

The third line is where the magic starts to happen. It says, “look at the ‘HTTP_HOST’ variable and see if it matches ‘airplanesarecool.com’. The “[NC]” means the test is case-insensitive.

If this condition is met, the fourth line redirects the user to index.php?p=180, where 180 is the ID of the WordPress Page or Post. The “QSA” is needed to preserve query strings.

SEO Implications

Domain mapping does present a dilemma for SEO. You probably want the canonical URL of your mapped pages to be the mapped domain, not the original WordPress domain. But, WordPress doesn’t know you mapped the page, so most SEO plugins will just use the original WordPress domain by default.

Luckily most SEO plugins give you the option of overriding the canonical URL with one that you specify. I wasn’t able to get this working properly with Yoast, even though it has the setting. It did work using The SEO Framework plugin for me.

Bottom line, remember to set the canonical URL of your mapped pages in your SEO plugin.

Conclusion

That’s it! Let me know how this worked for you, or if you have any questions, or if you have any corrections or improvements. – Brian

Brian Shim

I am a freelance web developer and consultant based in Santa Monica, CA who uses WordPress, PHP, and JavaScript to create websites and web applications for businesses, nonprofits, and organizations.

brianshim.com