Migrating to a new site can bring a lot of stress to a company. There’s content and design considerations, budgets and timeframes to stick to all slathered with a load of confusing acronyms like .net, java, CMS so it’s not wonder that another critical term gets forgotten.


In the course of website development amongst all of the very exciting and engaging visuals and tech talk, website traffic is assumed to be something that will just come as a matter of due course with the new website. Any why shouldn’t it? It’s going to be new! Beautiful! Easy to use!

If you’re at a great digital agency then their SEO team will pop their hand up and offer to ensure that this new, beautiful and easy to use website can still be found post-migration. After all there’s a whole raft of users that will need to be impressed by it.

So, at this critical juncture your SEO team should be developing a list of 301 redirects that will preserve your organic traffic and ensure minimal impact to sales and leads when the new site is cut over to. While it’s not as exciting and flashy as the new visuals will be, it most certainly will be one of the most critical tasks to ensuring the maintenance of your traffic status quo.

What is 301 URL mapping?

301 redirect mapping is the process of pulling all the URLs from an old website that are generating any website traffic, either from a link on another website or through a high ranking in a search engine and pointing them to an equivalent URL on the new website.

It ensures that all of the traffic that might come from that link get sent to a resource on the new website that is relevant to the user. A user clicks on a link that once sat on the old site and is seamlessly sent to the new website instead.

For example:

Say I have a page on my old website www.bluewidgets.com/cart/blue-widgets. When I move to my new website, there is no /cart/ section of the website. Instead /cart/ has been replaced with /shop/ and looks like www.bluewidgets.com/shop/blue-widgets.

Without ensuring that I have correctly mapped all of URLs on the old website to the new structure, I will lose valuable website traffic, and therefore revenue, when I cut over to the new URL structure. My data, that I correctly set up in Google Analytics, show a huge drop off in traffic. All the links that my customers had stored in their browsers as bookmarks, all of the links in search engines and on other website that used the old /cart/ syntax will be broken, sending users to a dreaded 404 page. Thankfully with good 301 redirect mapping, this loss of traffic an revenue can be avoided.

When should a 301 redirect map be done?

If you are fortunate, mapping 301 redirects wont be necessary. For some very small website without much organic traffic or you are doing a simple hosting provider change that will maintain the URLs as they are from the old to new provider, then you might be able to skip this step.

For the rest of us, pulling a list of the old website’s URLs using a tool like Screaming Frog will be necessary to ensure that we can plan to have this mapped out at the start of the discussions about getting a new website up and running. They have a handy guide on how to pull this list on their website.

Use Get Redirects 301 Redirect Tools

I recently came across Get Redirects while looking for tools to help me with my 301-redirect mapping. They have an excellent, easy to use tool that you can use for free. It’s AI driven, runs in browser and is free during it’s early access. Its now my ‘step 1’ for all redirect mapping.

Once logged in, just add your old website, define if you want to use the current sitemap if relevant, or you can upload a list of URLs from a spreadsheet if you know which URLs need to be redirected.

Then do the same for your new website:

Hit “Next” and then the tool will server you up a spreadsheet file to download and manipulate – old website URLs on the left and their associated new website partner on the right.

I found that once the confidence level metric dropped below about 60 then some of the redirects looked a bit sketchy, but that was more due to there being a mismatch in the content between the old and new website rather than the tool being an issue. Where pages were present on the old and new site Get Redirects gave remarkably accurate results.

Still, I tested it for large ecommerce website that needed multiple country sub-folders redirected to the new parent country TLD and was pleasantly surprised by the amount of time that I saved. For a free early access tool it runs smoothly and the support team were able to resolve a caching issue for me very quickly.

301 mapping with Microsoft Excel

I will boot up my Get Redirects list in Excel to give it a once over. I skim over all of the higher confidence level redirects to double check they are suitable and export those to another tab for ‘safe keeping’ while I work on the list once I hit a level where the redirects seem to start to not match.

This will involve the tried and tested ‘filter’ method. Try and group all of your old URLs into buckets that would be suitable to be sent to one of the new URLs. You might have had a lot of old outdated blog posts about a product you don’t support anymore, so using the filters search feature find all of these and mass update them to a page that may be suitable.

This is something that Revium’s SEO team had to do for a recent client as they had restructured some of their product offerings and the most relevant product URL on the new site was the category page.

It’s worth noting here that these will be treated as a ‘soft 404’ by Google, but my main concern was ensuring that traffic loss was minimised. A link back to a somewhat relevant page on the new website was much better than receiving a generic 404 page, so I made the call to spend the time updating these, even though there would be no ‘link juice’ passed on.

Once all of the one-offs and unique cases have been handled, it’s time to clean up our list. In the case where you have received a number of 301 redirects from various sources, you might find that there are some duplicate 301s from the old website. Easily filter these out with Excels remove duplicates feature before passing on to your development team.

After the 301’s have been implemented it’s a good idea to test the list with a tool like Screaming Frog to check all the response codes. Look for any of the new URLs that return a 301 code (there may be circular redirects) or a 404 code and update as needed.

With a well executed 301 mapping plan you should be able to minimise the traffic loss when you switch websites. While some traffic loss is almost inevitable to avoid, you can stem this as much as possible with some forethought and planning.