A/B Testing for SEO

01 November 2021
by Archie Williamson
5 mins
A/B Testing for SEO

A/B testing for SEO is a process where you compare two different versions of a web page concurrently to determine which one performs better, with the view to making permanent changes that can improve your search rankings.

Also known as split testing, this process enables you to see how tweaking different elements on a web page can alter search performance. The original web page that is currently live on your site is variant A, while the test page with changes to elements such as title tags, content and links is variant B.

A/B testing is essential for supporting a robust SEO strategy because small changes to a web page can have a significant impact on rankings and visibility in search, as well as your traffic levels and conversions. If you don’t test the changes you want to make, your site could suffer and you will be left scrambling to revert them.

Google gives a brief overview of A/B testing with its own best practices for website testing. It notes that multiple versions of a page can be created when testing and that each of these will have a unique URL. Some users are redirected to these different versions when they load up the original URL, and their behaviour and actions are tracked and can then be compared for each one as a result. This allows you to see what changes are the most effective.

What is multivariate testing?

Because there are so many page elements to optimise for SEO, just changing one and then testing it is not a viable method as it would be laborious and time consuming. Multivariate testing is the solution here as it allows you to test multiple sections of a page to see what’s best. This allows you to mix and match images, headlines, CTAs and even button placements to find the right combination.

Even more useful is that multivariate testing brings all the variations together within a single URL, as different elements and sections are inserted dynamically each time the page is loaded. You can conduct a multivariate test (MVT) and create different combinations for a page for SEO purposes by using software such as Google Optimize. You can then use Google Search Console to keep track of the findings.

Why is A/B testing important for Google and Bing?

Just as you want your site to be stable, consistent and reliable for visitors, Google expects the same from you. After it has crawled and indexed a page and then served it to users in search results, it wants that page to represent the user experience it expects. Google’s SEO expert, John Mueller, says unexpected changes to pages are a “bit awkward for us”.

He recommends always showing Google’s crawlers the version that users will eventually see. Mueller adds: “What I wouldn’t recommend doing is randomly switching that version because that makes it a lot harder for us to actually index your pages properly.”

This is because pages with different test URL variations can lead to Google seeing different versions of content and elements effectively changing on the fly, going back and forth between each one. Google recommends using a rel=’’canonical” tag on the original page so it knows that this is the preferred version.

Bing echoed Google’s sentiments on attempting to always show variant A to its search bot, noting that stability is the priority. Bing’s Principal Program Manager, Fabrice Canel, says: “In the case of SEO, I recommend running experiments over the course of weeks, not hours, to truly understand the impact and limit the scope to versions A and B… not A, B, C, D, X, Y and Z.”

What are the best use cases for SEO A/B testing?

It’s possible to A/B test a range of different elements on websites, but for SEO, you should focus your efforts on aspects that are linked to Google’s search algorithm. Anything that could improve your rankings should be considered fair game for tweaks and overhauls. However, because keywords are fundamental to SEO and optimising your content for audiences, site elements that can boost keyword rankings should take precedence.

Title tags and meta descriptions

Title tag changes have a direct impact on key metrics such as click-through-rate (CTR), so it makes sense that you’d want to test different versions to see which one hits the right notes with audiences. Google actually provides an ‘expected CTR’ figure within its tracking tools. If your landing pages are not getting enough clicks, it might be time to test title variations to improve your rankings.

The same is true for meta descriptions, which can be optimised with important details, keywords and specific character lengths to better match search intent. You can do this yourself or outsource to agencies offering SEO services to improve the quality of your content and these on-page elements. When you have created a new copy, you can then start A/B testing it.

Updating content and internal links

If you want to upcycle an article or blog and add sections to it to increase its topical depth and make it more relevant to user queries, testing the two versions is preferable before you go live with the updated page. While you may think the changes are the right ones for the topic at hand, A/B testing will make sure that Google is responding to the higher quality signals and that rankings are improving as a result. Comparing different variations of internal links can also increase your Page Rank and help you to optimise your site architecture.

Adding new pages and features

An extension of new content, adding groups of fresh pages is a key part of keeping your site up to date and relevant. But it is a good idea to test how Google crawls and indexes these pages, and to determine the scale of the impact on your current rankings in search. For even bigger changes like site migrations and technical overhauls, A/B testing is critical. And before you conduct any test, make sure to complete a site snapshot and backup.

Split testing allows you to implement changes to your web pages and determine whether they will have a positive impact on your search rankings. We can help you with the process. We offer a free website audit that can highlight SEO elements you could improve for testing, and content creation services to increase the quality of them. Contact us today to find out more.


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