As web developers look for new ways to deliver fast and beautiful web projects, an ever-growing trend has been the implementation of a single-page application framework. But what is a single-page application, and why should you consider them for your next project?

Obviously, a single-page application (or one-page website) is an application or website that is limited to a single page. What that means in theory and function though, is that a website or application is built to re-render its content and/or design without sending a request back to the server for a new HTML page. All of the HTML and CSS required for the entire site interaction is loaded when the application is first launched, and then the page changes and updates as the user interacts with it, without loading any new code. This, in theory, leads to faster navigation and a quicker, smoother user experience – or, at least, it should do.

How do single-page applications work?

With more traditional application and web development, each time a user wants to load a new page, or interact with certain areas of a page, the site needs to send a request back to the server to load the next thing that the user is trying to do. Simplistically, single-page applications can load the desired piece of content or design without having to go back to the server.

In many websites, lots of the data on the page will stay the same as you browse between pages – think headers, footers, menus, etc. The only parts of the page that change are the things a user interacts with. Single-page applications load these parts of the page dynamically with JSON data and AJAX requests. This means that data conversion moves from server-side to client-side, and speeds up website performance.

Why use single-page applications?

Single-page applications are increasing in popularity, particularly among start-ups and tech companies. Some benefits of single-page applications are:

  • Better UX: A more streamlined interface where things only load if they have to will result in an improved user experience.
  • Faster performance: Eliminating requests to the server means “new pages” will load faster, and a user’s journey will be quick and smooth.
  • Simplified deployment: With a minimum of three files to serve (HTML, CSS and JavaScript files), the application’s deployment will be much easier.
  • Cost savings? It obviously depends on implementation, but because single-page applications send fewer server requests, there’s less impact on server resources, which ultimately saves money.

What are the disadvantages of single-page applications?

Although there are many benefits, single-page applications do have their downsides:

  • Unfamiliar usability: This sort of counteracts the general “Better UX” benefit, but if a single-page application is implemented poorly, it can lead to an unfamiliar and frustrating user experience. For example, web users have a certain expectation of what should happen when they click the refresh or back button in their browser. A good single-page application framework can mirror this functionality, but a bad one can lead to users exiting the page completely – and possibly never returning.
  • Unsaved changes: For things like forms that require user input, traditional applications can warn users that they’re about to lose unsaved changes – this is trickier and sometimes impossible with single-page applications.
  • SEO/analytics: Search engine optimisation (SEO) is fiddly with single-page applications, because as far as the crawler is concerned, there is only one page. This makes it hard to figure out what all of that content is trying to rank for. Similarly, in terms of tracking traffic it’s much harder to analyse which users get to which part of the website.
  • Bloated load: Although they give improved performance once the application is up and running, the extra code required to make single-page applications work is going to bloat the initial page load time.

Should you use a single-page application for your web project?

The answer to that question depends on whether the positives of single-page applications outweigh the negatives for your specific project. But just remember, fundamentally, a user doesn’t really care how the interface is coded, rendered, or delivered, they just want it to load fast, and be easy to navigate.

Whichever way you decide to build your web project, you’ll need a fast and reliable way to host it. For all the latest advice on website maintenance, head to our blog. Or for CloudNX, our scalable and reliable next-generation cloud hosting platform, get in touch with our dedicated team.As web developers look for new ways to deliver fast and beautiful web projects, an ever-growing trend has been the implementation of a “single-page application” framework. But what is a single-page application, and why should you consider them for your next project?

In this blog post, we’ll break down how SPAs work, when to use them, and where they fall short so you can make the right call for your next build. Read on to find out more.

What is a single-page application?

A single-page application (SPA) is a website or web app that loads a single HTML page and dynamically updates it as the user interacts with it. Unlike traditional sites, where every interaction sends a request back to the server to load a new HTML page, SPAs load everything they need upfront. Content, styling, and functionality are handled client-side, meaning the browser manages changes in-page without needing full reloads.

This allows for smoother navigation, faster transitions, and a more app-like user experience (provided the site is built correctly).

How do single-page applications work?

Traditional websites rely on server-side rendering. Every time a user clicks a link or submits a form, the server processes the request and sends back a brand-new page. SPAs flip that logic. Most of the site’s code (HTML, CSS, JavaScript) is loaded at the start. When a user interacts with the site, JavaScript updates only the relevant content using AJAX and JSON.

For the user, this means less waiting and smoother transitions. Elements like navigation bars, footers, or headers stay consistent, while only the key content blocks change. 

In many websites, things like headers, footers, and menus typically stay the same between pages. The only parts that change are the things a user interacts with. Single-page applications load these parts of the page dynamically with JSON data and AJAX requests. This means that data conversion moves from server-side to client-side and speeds up website performance.

Why use single-page applications?

Single-page applications are increasing in popularity, particularly among start-ups and tech companies. Benefits include:

  • Better UX: A more streamlined interface where things only load if they have to will result in an improved user experience
  • Faster performance: Eliminating requests to the server means “new pages” will load faster, and a user’s journey will be quick and smooth
  • Simplified deployment: With a minimum of three files to serve (HTML, CSS and JavaScript files), the application’s deployment will be much easier
  • Cost savings: When implemented correctly, single-page applications send fewer server requests and have less impact on server resources, which ultimately saves money

Common use cases for SPAs

Single-page applications are best suited to applications where users spend time interacting with the interface rather than jumping between lots of different pages. For example, dashboards – such as internal tools where the data updates often but the layout stays the same – are a common use case for SPAs. 

Similarly, webmail interfaces like Gmail or Outlook use SPA structures to deliver near-instant interaction, while project management tools like Trello or Asana benefit from the real-time responsiveness SPAs provide.

If your site is built around real-time data, frequent updates, or rich interactivity, a single-page approach is often the right fit. SPAs excel in scenarios where seamless user experience and dynamic content are prioritised over traditional page reloads.

What are the disadvantages of single-page applications?

Although there are many benefits, single-page applications do have their downsides:

  • Unfamiliar usability: If a single-page application is implemented poorly it can lead to an unfamiliar and frustrating user experience. For example, web users have a certain expectation of what should happen when they click the refresh or back button in their browser, which a good SPA imitates. A bad one can lead to increased bounce rate.
  • Unsaved changes: For things like forms that require user input, traditional applications can warn users that they’re about to lose unsaved changes – this is trickier and sometimes impossible with single-page applications.
  • SEO/analytics: Search engine optimisation (SEO) is fiddly with single-page applications, because as far as the crawler is concerned, there is only one page. This makes it hard to figure out what all of that content is trying to rank for. Similarly, in terms of tracking traffic it’s much harder to analyse which users get to which part of the website.
  • Bloated load: Although they give improved performance once the application is up and running, the extra code required to make single-page applications work is going to bloat the initial page load time.

Should you use a single-page application for your web project?

It depends on whether the positives of single-page applications outweigh the negatives for your specific project. SPAs can deliver a great experience, but only when used in the right context. Here are some examples that should show you what we mean.

SaaS dashboard

Let’s say you’re building a project management tool where users spend a lot of time logged in, switching between boards, tasks, messages, and analytics. Most of the interface stays the same, and users expect fast, app-like interactions. A single-page application works well here because it allows instant updates, fewer page loads, and a smoother experience. Performance, not SEO, is the priority.

Marketing website

Or, let’s say you’re launching a product with a blog, pricing pages, FAQs, and contact forms. Most users will find your site through search engines, so it’s important for every page to rank independently. In this case, a traditional multi-page setup is better. It’s more SEO-friendly, and you don’t need the dynamic functionality of a full SPA.

Fundamentally, users don’t care how your site is built. They care about speed, usability, and being able to find what they’re looking for without hassle. The right setup is the one that delivers that experience consistently and reliably.

Host faster, whatever your setup

It doesn’t matter if you’re building a lean single-page app or a multi-page site with heavy server logic – whichever way you decide to build your web project, you’ll need a fast and reliable way to host it. For all the latest advice on website maintenance, head to our blog or get in touch with our dedicated team.