Many of our web development contracts involve replacing old web sites rather than developing web sites on new domains. So what is the best practice when replacing an old web site with a new web site? Specifically, how do we ensure that the valuable incoming links to the old site still benefit the new site in search engine optimisation terms? And at the same time, how do we ensure that when someone clicks a link to a page on the old site that they arrive at the same (or corresponding) right page on the new site?
Get this right, and you can replace a web site with barely a blip in the traffic. Get it wrong, and it can take weeks for your traffic to recover.
The good news is that it's not complicated! Here's what you do.
Step 1 - creating a content map
First, you map the pages on your existing site to pages on your new site. This is as easy as it sounds; in a spreadsheet, just cut and paste in the address of the existing page, and alongside it paste the address of the new page.
Obviously there won't always be perfect matches, but don't worry about that. Pick the nearest match you can.
If you're lucky, you'll be able to manage this URL mapping process in your content management system too, as shown here in the Nemisys CMS.
Step 2 - redirecting the old pages to the new
Next, give this spreadsheet to your web developers and ask them to set up redirects from the old page to the new page. But be very specific about this; ask them to use an HTTP 301 redirect. This tells Google and the other search engines that the page has permanently moved, and that they ought to index the new page.
First, any incoming links pointing at pages on your old site will now (in the search engines' eyes) be pointing at the equivalent page on your new site, so protecting your search ranking.
Second, anyone clicking on a search result, they will go straight to the new page instead of seeing an error.
You can see for yourself. This links to a page on our old web site. Clicking it (just as you might do on another web site if it had linked) will take you straight to the right page on our new web site.