What is a headless CMS?

In a sentence, Headless CMS architecture separates back-end content functions (like creation, management, and storage) from front-end functions (like presentation and delivery).

Before we get too technical, let’s start with what this means in context of brand experience.

Headless architecture is partly a response to the way the relationship between web content and content creation has evolved. For a long time, most web content was delivered through a browser, often as a web page. But new connected devices are arriving all the time and audiences are consuming content through different user interfaces, like smart devices, wearables, AI-enabled voice assistants, and virtual reality (VR) headsets.

Headless CMS architecture is foundational to addressing these new content challenges. It means you can easily create and manage as much content as your audience demands and embrace an omnichannel approach that delivers content to all relevant touchpoints.

Headless CMS: Front end vs. back end

Traditional, monolithic content management systems have two halves: one front and one back.

Broadly speaking, the back end of a CMS relates to how content is managed, and the front end relates to how it’s presented. Think of it like a storefront window display.

Front-end tasks include everything you’d see as you peered in from the street: the selection and arrangement of products and branding.

Back-end tasks include logistics — making the signage, storing the inventory, and managing the movement of goods around the store.

So, for a basic website, the back end might include:

• A simple interface to create content
• A database to store digital assets
• An application layer to create and apply design frameworks

The front end would then pull through content, stored assets, and designs and publish them to an HTML page.

What is a decoupled CMS?

With a traditional CMS, the front end presentation, also known as the presentation layer, and back end were tightly locked together. Users could create, store, manage, and publish content all within a single interface.

For non-technical users and content editors publishing simple content — for example, a WordPress blog — this was a great, seamless setup.

But as digital experiences and ecommerce continues to evolve, developers are spending too much time creating custom workarounds to optimize experiences and deliver more sophisticated content across devices.

Decoupled CMSs split back-end and front-end tasks. In practice, this means developers can quickly code and design front-end experiences in their preferred language without being bound by restrictive back-end technologies.

Instead, they can use RESTful API or GraphQL API to connect the back-end functions — like content storage and management — to any front-end delivery environment.

What is an API-first CMS?

Where decoupled CMSs separate back-end and front-end functions, they often still include some front-end delivery tools, such as page templates or module integrations.

API-first CMSs are functionally the same as headless CMSs in that they have no default front end. Developers are free to create as many delivery layers as needed, (in whatever language they prefer) to push content to any new channel imaginable.

API-first CMSs are great if you have a team of skilled developers ready to go—the CMS simply manages content and waits for an API call from a front-end delivery layer built by the development team.

Decoupled CMSs, on the other hand, suit companies who want the flexibility of a separate front end and back end, but who might still need some publishing support.

Headless CMS solutions are undoubtedly the future of content management, for two important reasons:

1. Digital content and content creators are getting more sophisticated, and users’ expectations are rising. To stand out and deliver exceptional customer experiences, you need to build beautiful, responsive, and interactive content — and you need to be able to do it quickly.
2. New digital channels, content types, and user devices are emerging all the time. It’s not enough to build beautiful stuff — you also need to make sure you can deliver it everywhere, as efficiently as possible. SaaS-based headless CMSs mean marketers and developers can build amazing content today, and — importantly — future-proof their content operations to deliver consistently great content to websites, mobile apps, and all relevant touchpoints.

By embracing structured content and content modelling in a headless CMS, brands can improve their content operations and provide a better user experience for their customers.

It’s great for marketers because…

…they can create content once while enabling their developers to display it anywhere. That means less time spent on administration and more time for building beautiful, cohesive experiences.

By making it possible to reuse content, the centralized content hub removes manual processes, like copy and pasting. Marketers and content creators can also edit once and share the update anywhere.

It’s great for users because…

…the end user experience always feels fast, consistent, and responsive. That’s because the client side doesn’t need to communicate with the back-end system — it just has to render content.

It’s great for developers because…

…they’re released from the back-end restrictions of programming languages where they lack expertise. Instead, they can build the look, feel, and functionality of user experiences using tools they know and like (e.g. JavaScript libraries and frameworks), and then push content out anywhere using the latest APIs.

Developers have the flexibility to choose their preferred front-end framework and there are various options available for Static Site Generators, for example, Next.js, Gatsby.js, and NUXT.js. In an open-source headless CMS, developers can access code (JavaScript, PHP) to create their own API calls and templates.

Off-the-shelf, headless content management systems aren't a magic bullet to fix all your content challenges. They can come with two major trade-offs that need to be seriously considered.

For one, what you gain in flexibility from this type of content repository, you lose in accessibility. Since presentation is left to developers writing JavaScript, non-technical marketers can’t use What You See Is What You Get (WYSIWYG) authoring or editing.

The second one is bigger.

Something drastic happens when you cut the head off a CMS: you sever the ability to send customer interaction data between the front end and the back end in real time.

That means you can’t personalize experiences or run content analytics activities.

Personalization has gone from a “nice-to-have” to a table-stakes requirement. Customers are learning what great personalization feels like from industry leaders like Amazon, Netflix, Spotify, and others.

If you can’t provide a similar experience, customers will likely go elsewhere — and soon. So what’s the answer?

The ideal CMS architecture would combine the flexibility and extensibility of headless CMS platforms with the personalization and content analytics capabilities offered by traditional coupled CMS.

That’s exactly what Sitecore's composable, headless delivery options provide.

Multiple headless options support front-end developers as they build solutions and apps that render content on any device or browser. Whether using JavaScript libraries such as Vue.js, React.js, and Angular.js, or leveraging the new ASP.NET Core SDK and headless rendering host architecture, developers can choose what's best for them.

These options also come with an API that connects to Sitecore’s contextual content delivery server, so users see personalized content based on profile information, past interactions, and more in real time.