Headless vs. Monolithic CMS: Which Delivers Better Website Performance?
Storyblok is the first headless CMS that works for developers & marketers alike.
)
Website performance is an absolutely decisive factor in evaluating any web project’s success. Great performance has a very direct business impact, as it significantly influences the user experience, boosts customer satisfaction and retention, contributes to search engine optimization (SEO), ensures scalability as your business grows, and improves the conversion rate. Hence, ensuring that your website is lightning-fast and stays that way is a crucial goal that should inform your choice of technology stack (i.e., frontend framework, CMS, hosting platform, etc.) in a very substantial way. In this article, we’ll explore the role of the CMS, establish its potential impact on performance, and find out whether choosing a headless CMS guarantees better results.
Website performance: what is it and how to measure it
As stated by MDN, “Web performance is the objective measurement and perceived user experience of a website or application.” Importantly, performance can be evaluated by objective measurements, such as the time it takes for a website to render and become interactive, and also subjective measurements, gauging how long it actually feels until the website becomes fully operational. Google Core Web Vitals are a commonly used set of metrics to assess the real-world user experience with regard to performance. Common tools that can be used to evaluate and monitor your website’s performance are WebPageTest and PageSpeed Insights. It is good practice to conduct such tests regularly, for instance, as part of your continuous deployment workflow.
How a headless CMS can positively impact performance
Modern frontend frameworks
As discussed in our article How to Choose a Tech Stack when Migrating to a Headless CMS, using a headless CMS provides you with complete control over what frontend framework and web development language you want to utilize. Whereas monolithic CMSs typically require you to use legacy technology to render the front end, modern web frameworks such as Astro are built with cutting-edge performance in mind.
However, it is important to research what technologies are officially supported by the headless CMS provider. While it is generally possible to fetch content from a headless CMS with almost any web technology, a tight integration via an official SDK provides a substantially improved developer experience (DX).
Storyblok maintains an open-source SDK ecosystem for many modern web technologies, emphasizing a streamlined DX. This makes evaluating different technologies a breeze, allowing you to find the perfect one for your project quickly.
Rendering modes
Closely intertwined with your chosen frontend framework, you can choose a suitable rendering mode for your website. Importantly, static site generation (SSG) offers best-in-class performance. Most modern frameworks enable you to rebuild the whole site and deliver it statically upon content changes. This process can be conveniently automated using the webhook functionality typically provided by a headless CMS.
One caveat of SSG is that build times increase as the amount of content grows. For projects with thousands of content entries, it can be advantageous to employ server-side rendering in combination with a solid caching strategy. Some web frameworks also offer a hybrid mode, rendering some sections of the website statically and others on-demand. This can be a viable strategy if you can anticipate that some sections only require periodic updates (e.g., content such as an about or services page, legal notice, etc.), whereas others are highly dynamic (e.g., press releases, news, blog entries, etc.).
Full control over the DOM
With a headless CMS, you get to enjoy full control over the document object model (DOM). It is important for performance to keep the element structure lean and efficient, avoiding unnecessary complexity, nesting, and bloat.
API-first approach
Headless CMSs typically provide state-of-the-art APIs with excellent performance, global CDNs, and robust caching, allowing you to deliver vast amounts of content as quickly and efficiently as possible. When evaluating different headless CMSs, it is advisable to study the API's technical limitations (e.g., number of API calls per month, rate limit, maximum response size) carefully to ensure that they fit the project’s requirements.
Built-in DAM
Some headless CMSs provide powerful built-in digital asset management (DAM) capabilities. Unoptimized images are one of the most important factors that can have a very detrimental impact on website performance. As a developer, you enjoy a lot of control when dealing with static assets. However, as soon as content creators and editors enter the picture, a very large image could easily be requested on an otherwise perfectly optimized landing page, significantly clogging performance.
With Storyblok, you can enjoy the perks of the Image Service, which allows you to programmatically resize and optimize images on the fly, distribute them using a global CDN, and much more. This ensures that any large image is delivered as a WEBP in dimensions that suit the layout requirements. Learn more about the Image Service and its possibilities in our interactive documentation.
Caveats of a monolithic CMS
First of all, it is important to point out that achieving great performance with a monolithic CMS is entirely possible. For example, it is possible to implement very aggressive caching strategies or employ static site generation plugins that may be provided by third-party vendors. Similarly, you could serve assets via a global CDN using an external DAM provider. Generally, this process is more fiddly and error-prone, as it can rely heavily on third-party integrations and tweaking server settings.
The area where a monolithic CMS falls short the most is the amount of control you can exert over the presentation layer. Many such CMSs introduce a lot of unnecessary bloat to the DOM, which can be burdensome or even impossible to remove. This is particularly the case when working with CMSs that offer page builder functionality.
Does a headless CMS guarantee better website performance?
A headless CMS does not guarantee great website performance, but it provides some of the fundamental building blocks required to achieve it and doesn’t stand in your way. It is important to understand that website performance is highly implementation-specific and requires a significant level of expertise. Regardless of the chosen CMS, it is highly advisable to obtain a very robust understanding of web performance best practices, as this can really make or break the success of any web project.
It is possible to build a fast website driven by a monolithic CMS, and a slow website powered by a headless CMS. However, if utilized correctly, choosing a headless CMS in combination with a performance-optimized web framework will always deliver the best results.
Choosing Storyblok means that you gain immediate access to fantastic DX for a variety of modern web technologies, a built-in DAM, and lightning-fast APIs, ensuring that your performance journey is seamless and joyful.
