As with many SEO related questions, the short answer is, “It depends”. The first thing to clarify is what “changing” means. Outside of changes to content, keyword usage and incoming links, common changes to a web site that affect search engine visibility include:
- Changing domain names
- Changing content management systems
- Changing design
- Changing web hosts
Companies change domain names for many reasons including: improved usability or better domain name (360digiworld.in to 360digiworld.com) , the result of a company acquisition, business roll up or simply changing the name of the company.
If search engines are indexing the current domain name and web pages, it matters a great deal how the implementation of a new domain name is handled. See this post, “The Cost of No SEO Migration Plan” for a good example of what not to do.
What should you do? If nothing but the domain name is changing, then a proper system of 301 redirects is in order along with identifying top link referring sources of traffic and asking them to change their links to use your new domain name.
What’s important is to make it easy for search engines to understand that you’ve made a permanent change from one domain to another and to retain as much “link equity” in that change as possible. There are other considerations with domain name changes that you can find in the resource links below.
Changing content management systems and web design are the most common things that affect search visibility amongst the list of issues listed above. I would highly recommend reading “Site Re-Design? Call Your SEO Expert First!” to get a good handle on the good and bad of factoring how an updated web site should consider search engines.
Most companies engage a web design agency or in-house design staff to create the new web site with an emphasis on front end usability for customers and ease of use/maintenance on the back end site management. What they often FAIL to consider is how changing URL syntax (ex: webpage.htm to webpage.php or webpage.aspx) will confuse search engines.
A map of old to new URLs needs to be implemented along with a system of permanent (301) redirects. As with a changing domain name, top referring link sources should be identified from web analytics and contacted if necessary, to change what URL they’re linking to.
Pages that cannot be mapped need to be dealt with using custom 404 error pages which should be user and search engine friendly. After the CMS and site design and redirects have been implemented, it’s important to continue monitoring web analytics for broken links and 404 errors so they can be fixed.
Changing web hosts alone shouldn’t have any affect on how a search engine ranks the web site as long as the change is smooth. A small static site with few web pages (under 1,000) is pretty straightforward. Moving a huge site with tens of thousands of pages, multiple servers and more complex hosting and redundancy factors is of course, a bit more complex.
Fundamentally, changing web hosts should involve setting up the site at its new location completely, then making DNS changes to point the domain name to the new hosting location and ensuring search engines are properly crawling the web site at its new location. Then and only then should you close down the old hosting location.
The bottom line with mitigating negative SEO effects due to web site changes is to make sure search engines are considered along with customers and web site operators. Search engines are pretty smart on many things, but they’re still pretty “dumb” when it comes to dealing with many of the routine changes that web site owners make. They key is to make it easy for search engines to understand the changes being made. Otherwise you might end up with the symbolic equivalent our large, hairy guy above showing up in your moving van search results.
If you make it easy for search engines to understand the changes being made and what domain, URL syntax, site structure, hosting location and link sources they should pay attention to, then the search engines can do a better job of adjusting with minimal effect to rankings.
If a site owner doesn’t have staff in-house or within their web design agency that are experienced with making these kinds of changes that consider the effect on SEO, then it makes sense to engage a competent and experienced consultant for a SEO migration plan that will work with the design and web development teams. By doing so, many, many expensive headaches can be avoided.