Demystifying Edge SEO

Published on October 8, 2021 by Chris Ainsworth

Over the past few months, I’ve observed increased chatter in the industry and heightened intrigue from clients surrounding the concept of “Edge SEO”. There seems to be a belief (perhaps, by some) that edge SEO is a remarkable new technology that will change the face of SEO. But what is this newfound magical and mysterious technology and how can we benefit from it?

Edge SEO Isn’t New

First things first – the concept of Edge SEO (or ‘SEO on the Edge’) isn’t new.

The first time I heard of edge SEO being discussed publicly was back in 2018 when Dan Taylor discussed using Cloudflare Workers to implement hreflang at TechSEO Boost 2018.

So, it’s been around for a while now and there’s quite a lot of pre-existing information on the web from notable industry experts and leaders.

Edge SEO doesn’t change what we do as technical SEOs, it simply changes how we do it; or more to the point, it provides another avenue to achieve tasks when traditional routes may be blocked or congested.

What is Edge SEO?

So, what exactly this mysterious Edge SEO?

Edge SEO is essentially a technique of deploying code modifications (such as SEO technical fixes) via serverless technologies (otherwise known as ‘edge’ technologies) independent of the website infrastructure.

Still confused? In layman’s terms, it’s a method of deploying code-level website modification via 3rd party tools/systems without having to modify the actual underlying website code or server configuration (AKA the ‘origin’). Clever, hey!

Why Edge SEO?

Technical SEO plays a key role in the optimisation of any website, so it’s no secret that when done right, technical SEO can dramatically improve a site’s performance within organic search. From bot accessibility and crawl efficiency to redirection and mark-up, each element of technical SEO plays a vital role. However, the deployment of technical SEO “fixes” often presents a huge barrier.

Back in 2016 Will Critchlow published a study which found that SEOs often wait over 6 months for high priority technical changes to be deployed. Speaking from experience, that rings true. I’ve been practicing SEO for over 10 years and if I had £1 for every technical recommendation which has failed to be implemented, I would be a rich man!

This can happen for several reasons such as:

  • Congested Development Pipelines
    Let’s remember that there are often other important or critical website modifications in the pipeline which take priority.
  • Gatekeeper Web Developers
    Those unhelpful web developers who either don’t want to make the changes, don’t believe in the value of the changes, or who are precious about their code/system (sorry devs, but it happens!).
  • Legacy Platforms and/or Servers
    Sometimes the architecture is simply dated and it’s not feasible to deploy the necessary changes, or perhaps the system isn’t even capable of handling the proposed amends.
  • Budget / Proof of Concept
    Sometimes the client/organisation may not have the budget to invest in the modifications and may need a proof of concept before committing to the expenditure.
  • and so on…

Consequently, with technical SEO recommendations not deployed at the origin, organic performance is hindered, and ROI is inevitably restricted.

This is a problem for businesses of all shapes and sizes. Congested development pipelines are often a problem for larger organisations where the website may be in a continuous state of evolution – our SEO recommendation may not be seen as the highest priority or perhaps simply must wait their turn in the queue. Whereas budget restrictions are often a concern for smaller businesses which may not have the financial flexibility for frequent or even one-off SEO amends; and therefore may require a proof of concept.

Whatever the reason, edge SEO can potentially help by bypassing congestion and eliminating reliance on origin modification. However, SEO on the edge is only needed when it’s needed – in cases where the origin cannot be modified. If it’s feasible to modify the origin rather than relying on edge SEO, that remains the preference.

Methods of SEO on the Edge

Content Delivery Networks (CDNs) provide the gateway to serverless (or ‘edge’) technologies with the edge being a layer between the origin and the user. One widely used CDN is Cloudflare which provides serverless applications called Cloudflare Workers:

Cloudflare Workers provides a serverless execution environment that allows you to create entirely new applications or augment existing ones without configuring or maintaining infrastructure.

Read more on Cloudflare Workers via

These “edge workers” facilitates the execution of JavaScript as its’ passed through Cloudflare’s CDN, thus allowing many SEO fixes to be deployed on the edge without modifying the website infrastructure. Similar technologies include Akamai EdgeWorkers and Fastly Edge Solution which operate in a similar manner.

The possibilities here are limitless and only restricted by the programming expertise of those creating the Cloudflare Workers. Want to configure URL redirection via edge workers? Doable. Want to amend content via edge workers? Doable. What to re-architecture an entire web page through an edge worker? Probably doable (though probably a little extreme!).

Is GTM on the Edge?

Similarly, Google Tag Manager (GTM) can be used to inject code changes with little or no developer intervention. GTM, which is often use for tag management such as deploying Universal Analytics, GA4, Google Ads conversion tracking, Facebook Pixels and much more, also provides the ability to deploy custom JavaScript to override the underlying code. Again, there are numerous GTM use-cases including modifying page titles, rewriting headings and many more.

The main difference with GTM is that GTM is not on the edge – it resides in a client side environment (or server side in the Google cloud environment if using server-side tagging), and a level of infrastructure modification is required. That is, the GTM script must be added to each origin page of the website for GTM to be utilized. Whereas Cloudflare Workers need no origin modification and resides as a layer between the origin and the client – but you do need to be running on the Cloudflare CDN!


Edge SEO offers new and exciting ways for SEOs to “get the job done” when presented with certain barriers or restrictions, and may revolutionise the implementation of SEO recommendations – though the barriers to entry are still high! Edge SEO can help in scenarios whereby origin modification is simply not feasible for whatever reason, but it is not a “magic wand” solution to avoid any/all developer intervention.

Chris Green, Technical Director at Footprint Digital, recently took part in Webinar with Dixon Jones of Majestic and various others discussing SEO on the Edge. If you’re interested in edge SEO, I highly recommend watching this 50 minute webinar:

Eager to learn more about edge SEO? Feel free to contact me directly if you have any questions or queries!

Feature image courtesy of Martyn Smith