SEO Considerations For Building & Migrating Subdomain

May 21, 2013

5 Minute Read

While developing and launching a new website (and simultaneously maintaining your current site) you don’t necessarily have to take a hit on your natural search presence. Follow these top-five tips to avoid any potential pitfalls when migrating a new site from a subdomain.

Top-5 SEO Considerations For Building & Migrating A New Site From A Subdomain

A Common Staging Site Scenario for Migrating a New Site from a Subdomain

For the sake of presenting a somewhat-specific example, let’s say we’re developing a new site on a subdomain ( with the goal of it eventually living at once completed and migrated.

1.) Check Your Robots.Txt File At The Beginning, End Of Staging

This simple (yet hugely-important) file allows you to block the staging site from being indexed by search engines before its ready for your search engine audience. So, make sure you’re creating a new robots.txt file that is specific to your staging site right at the start!

The correct robots.txt file directing search engines not to index any page on the staging site should live (with our established example) at Keep in mind that this robots.txt file will be specific to the staging subdomain, and won’t have any effect on the main domain’s robots.txt file.

Because this file tells engines not to index your site, make sure you DO NOT move it to your main domain while launching your new site. A separate robots.txt file should be created during the development process that will be ready for launch when the new site is completed. Far too often a new site migrates with the “Disallow All” directive because the staging site’s robots.txt file is accidently moved with everything else.

2.) Get Your Redirects Mapped Out For Old URLs

This is a critical step in maintaining SEO value during a redesign because chances are if you’re changing your site, you’re likely adjusting your URL structure as well.

Search engines need to be directed to where your old page content lives on your new site. 301 permanent redirects tell search engines where to find URLs that are changing on the new site. If your site doesn’t have redirects in place correctly, the old URL will return a 404 response code, meaning you’ll lose any external linking significance accrued at that old (now non-existent) URL.

For pages that are “going away” on the new site, redirect these URLs to the homepage so users and search engines spiders are still able to get to your site when following a link pointing to one of these old URLs.

Prior to launch, make sure all your redirects are in place (verifying that they are returning a 301 permanent redirect response code) to prevent any surprises upon migration to the main domain.

3.) Set Indexation Benchmarks For Comparison

Create a before-and-after launch report of the amount of pages indexed across the major search engines. If the number of pages on both the new and old versions of the site is roughly the same, make sure that number doesn’t unexpectedly dip for a prolonged stretch after migrating a new site from a subdomain.

With that rough number of to-be-indexed pages in mind, don’t be too quick to panic if your indexed pages number fluctuates for a while after launch, as search engine spiders may take multiple crawls to fully comprehend all the changes that have occurred on the newly unleashed site.

4.) Make A Timely XML Sitemap Update

Give search engines an easy guide to your new site from the start. Make sure a new XML sitemap containing your new site’s URLs is simultaneously created alongside the staging site and launched within 24 hours of transferring the content to the main domain.

5.) Set Realistic SEO Expectations For Timelines, Results

Having realistic goals in mind for a migrating a new site from a subdomain and its impact on your natural search presence will allow you to accurately interpret how search engines are receiving the changes, while allowing you to communicate expectations to everyone involved.

Results will take time to measureIt may take several weeks to gauge how search engines are taking to your new site, so don’t put too much emphasis on the first few days of data from analytics packages and SEO software. Though Google and other popular engines are crawling faster than ever before, multiple crawls and subsequent updates to the index won’t happen right away. Be patient even if your site is small and crawl friendly.

Expect drops if top performing natural search pages are changing URLs – This is especially true in the first days after launch. Search engines accrue relevancy at URLs, and if they change (even if a 301 redirect is in place) there’s a good chance a negative net effect will occur for rankings. These can rebound over time with continued optimization efforts.

You’re Well On Your Way To Maintaining Your SEO Relevancy!

These tips will ensure your natural search presence doesn’t cease to exist upon migrating a new site from a subdomain.

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The BFO Team

Here at BFO, we're always striving to bring you the latest and greatest in digital marketing insights and education. We're not ones to brag, but we've been lucky enough to be featured in all sorts of fancy publications and media outlets, strutting our stuff and showing off our industry expertise.