Technical search engine optimisation (SEO) describes the efforts of a webmaster to ensure their website is compatible with search engine guidelines, and can be indexed and ranked for keyphrase searches accordingly.
Whilst marketers perhaps best understand the implications of getting SEO wrong, it is often developers that implement technical SEO decisions. Although technical SEO is not as time consuming as ongoing optimisation such as link building, get it wrong and you can scupper the search performance of your website fairly quickly (indexing issues occur upstream of quality scoring).
In Econsultancy's newly updated SEO Best Practice Guide, the analogy of a train is used - no matter what the carriages look like (on-page content), if the engine (technical SEO) doesn't work properly, nobody will ride the train.
The most appropriate time to consider technical SEO is during a website's construction. If this doesn't happen, lengthy and involved technical SEO audits may be needed to identify and fix problems, with possible periods of uncertainty as changes are made.
However, technical SEO is not just about site build; updates by search engines and changes in your own business direction or customer behaviour may necessitate change, too.
Technical SEO considerations when creating and maintaining a website include the following.
Future-proofing the site architecture
As the website grows over time, the architecture has to be able to cope. Ideally, pages should not be buried too deeply (more than four levels down) within the site, which means planning a 'horizontal' site. This allows search engines to regularly crawl, cache and index pages.
Categorisation is a big part of site architecture in ecommerce, dividing a catalogue of products into categories and assigning URLs. Products may need to live in several categories, which brings further considerations such as canonicalization (see below).
Other decisions to be made include:
Canonicalization is the process of choosing a preferred URL when there are several choices for an individual page. Canonicalization issues often occur with the homepage (for example, if many different international URLs point to the homepage, or more simply if www.example.com and http://example.com do so).
Tags and redirects are used to solve these issues so that search engines do not understand such URLs to be evidence of duplicated content.
Pagination, often used for ecommerce categories when displaying lots of products, can create crawler issues, duplicate content (similar to canonicalization) or simply 'diluting' the relevancy of your content by spreading it further.
Again, using the correct meta tags is the key to ranking effectively for paginated content.
Namely, ensuring this doesn't happen (similar content competing in search and leading to lower positions overall) by understanding what content you want to rank highest and determining the correct structure for internal linking, subdomains and international sites to enable this.
Redirection is used to ensure users are served the most appropriate content for them, which could be contextualised for their location, language or device.
Site speed can be optimised in a variety of ways including content delivery networks, caching solutions, minifying code, asynchronous loading or using Google's Accelerated Mobile Pages (AMP) HTML, which does all of these things and more.
HTML can be enhanced to give specific specific information to web crawlers. This markup is needed to have content formatted at its best.