Building Single-Page Applications: Complete Guide

Single-page applications have made a name for themselves over the past few years. In many cases, they are even preferred because of the several advantages they offer. Using them, first of all, gives a feeling closer to using native apps which is great for end-user. For years, websites are being built based on full-stack solutions – both the frontend layer and full business logic were contained in a single code base.

Single-page applications usually work only as a “receiver” of logic created behind a remote API. It’s like a phone call – two people can be on completely different ends of the world and talk to each other. In the same way, a single-page application and a backend server can be in completely different parts of the world. Of course, from a performance standpoint, it would be best if both the frontend and backend were as close as possible, but that’s a topic for another post.

There are JavaScript libraries for building single-page applications. These are libraries that have been well established. Additionally, have been reliable for many years. So we don’t have to worry that something we use will not be supported after a while. This is also the easiest and most recommended way to create web apps. However, it doesn’t mean that it’s easy. The right team won’t find itself. You know that getting a few people together is not enough.

Often building a web application also requires investing in people with the web servers and dedicated backend skills. Well, unless you already have a backend ready, then the matter is clear. When working with traditional web pages it usually revolves around PHP programming language. In this case it is different. The API can be served from different sources.

The development process also looks different in the case of single-page applications than traditional. A lot depends on good communication between the backend and frontend. We are not only talking about code, but also about the team. That is why it is so important to have a team working on the code that knows what good communication means.

If we build the whole thing from scratch, most likely the backend will be created in parallel to the frontend. This requires planning in such a way as not to expose anyone to downtime. I would venture to say that more important than choosing technology is choosing the right team for the job. After all, it is human hands that will turn your idea into a working product. What javascript framework will support the frontend layer is not as important. In each case developers use plain JavaScript – JS libraries differ only in the way they work with them.

How to create a single-page application?

The process of creating a single-page application is a bit more complex than that of a “traditional website”. We have a strong division between the front and backend layers, which often requires hiring the right team to take care of both. We can create a proper API based on a headless system, which is typically the preferred way for less logically complex projects. Such systems work in a very similar way to traditional CMS such as WordPress.

However, they don’t handle the page view directly. They only expose the data under an appropriate API – REST or GraphQL. Of the two, GraphQL comes across as more “concrete”. However, REST seems to work better with web-type solutions in the long run. It usually doesn’t matter much what backend technology you choose. The right development team is able to squeeze the best out of everything. Moreover, if necessary, they will suggest what would be a better choice. Based on the complexity of the business logic, this process, falls between “slightly more complex” and “much more complex”.

By the way – 👉 WordPress 👈 can also work as headless. In such systems, we can construct the data models ourselves and build content based on them. The backend API is a great material for a separate entry, which we will certainly look into on our blog. Now you just need to know what options you have – and as you can see there are a few of them. If you have or plan to have native applications or other services, such backend API can even serve as the main data source for all such solutions. Well, thought-out solutions are much easier to develop.

In addition to such solutions, we have also Backend As a Service (BAaS) – such as Supabase or better known Firebase and of course dedicated solutions tailored to our requirements.

When it comes to the application on the front-end, because it is the main topic here – we have a huge choice of frameworks ready to support the work on our application. Most of them are based on the three most popular JS code-based solutions: React, Angular, and Vue.

The most popular single-page applications frameworks – how do they affect usability?

The absolute leader among solutions for single-page applications is ReactJS. Along with related frameworks such as NextJS, Gatsby, or the recently popular RemixJS. VueJS also has its own equivalents such as NuxtJS. In fact, no matter which framework we choose, we can get a similar end result. Thanks to server-side rendering these types of solutions seem to work almost instantly. As opposed to traditional pages where every click means downloading a lot of data anew and redirecting to a completely new address. For this reason, single-page apps are often designed to resemble traditional apps, hence they are often referred to as “web applications”. From the browser history point of view, even though the user sees changes in the page address, he doesn’t move between URLs. The user stays at one address, while the application takes care of proper routing.

Modern JavaScript frameworks also have server-side rendering mechanisms. This is used to generate a server-side page on demand. This is not by default, this is an option, so you have to take it into account. Without this mechanism, the SEO of our application is scrubbed to the bottom. Despite the fact that Google robot is handling JavaScript applications better and better. This also often requires additional work and knowledge, but it pays off in the form of a very fast working web app.

Sometimes it’s the case that SEO is not important to us. For example, if a single page application works with sensitive data or is used as an internal solution. Like Todoist or any web-based email client. Then we don’t need SSR, and all the work of the application is on the client-side – in the user’s browser. The entire application is then hidden behind a login form. The only way to get in is to have the proper permissions.

Such single-page applications are often the most efficient from the user’s point of view because they are not limited in any way by the SSR mechanism. The server sends only the code to the browser, which takes care of the rest. Actually, by default, spa frameworks is designed for this kind of operation. The SSR mechanism is additionally activate and made to work on the web server – because that is where all the magic happens. SSR is certainly something to consider early in the workflow – but if our application will be working with sensitive data, it’s unlikely to make sense.

New page load

Thanks to appropriate cache mechanisms, on subsequent visits the initial page load will be even faster than the first time. Of course, the first-page load will be quick. However, it needs to download basic data thus requiring more time. Each loading time following the initial one, will be much faster. When I write “cache mechanisms” I mean solutions on many levels. This is not only cache in the browser, but also on the server or in the database used by the backend.

To sum up – in building a single-page application, you have to pay attention to more variables. However, this will pay off in the form of a lightning-fast website – if, of course, the qualified development team of experts took care of it.

React single-page apps

React is undoubtedly the market leader. The lion’s share of web apps is based on this library. 👉 React 👈 actually isn’t a framework, it’s more of a JavaScript library. This is because a lot of the functionality isn’t out of the box. I think this determines its popularity. Many programmers prefer to have freedom of choice instead of an imposed pattern. However, it is not perfect – if you care about SEO, a better option may be to use one of the related solutions – NextJS, Gatsby, or RemixJS. Let’s focus on NextJS. Next has a Server-Side Rendering mechanism that allows you to generate a server-side static page on demand and send it to the user.

When it comes to SEO, it sends it to a search engine robot. This is a very good method for search engine optimization. You should not forget to optimize in other aspects, after all, just serving HTML for search engines is not enough. Next is also very popular because of its ease of deployment. As long as you choose Vercel, the infrastructure is provided by the framework’s creators. In other cases, it will be a bit more difficult.

Angular single-page apps

👉 Angular 👈 is a JavaScript framework from Google. Actually, it is the only single-page application framework on our shortlist. Staying a bit in the shadow of React is still a great option if you want to build a single-page application-type web app. It’s considered a bit harder to learn. This is probably due to the fact that is much more complex than React. It provides out-of-box routing or SSR mechanisms. Therefore, the programmer has to spend more time on it to achieve the desired results.

Vue single-page apps

A third almost equally popular solution is VueJS. In many ways, it is the fastest of the three and certainly worth considering when planning a single-page app. It is – like React – more of a library and a good foundation for the development process than a framework. Its strength lies in its simplicity. Like React, it has a related framework for building server-side rendering applications – NuxtJS.

Single-page web applications – examples

Being an internet user today, it is hard not to use single-page applications. They are almost everywhere. Google Maps, Twitter, Facebook – each of these sites is an SPA. They differ from traditional web pages even in the way we perceive them. It’s hard to define this impression, but it just feels “different”. I’m sure you’re familiar with this feeling – perhaps it’s because they run faster and feel more like traditional desktop or mobile apps. Single-page application architecture is different from the architecture of a traditional website. In the case of SPA, everything actually takes place within only one page. The URL only changes to improve usability and user experience – there is no change from the browser’s point of view. The whole page is a single code base that divides into reusable components.

The web today is full to the brim with such solutions, and more are popping up every day. One example is Google. Most of its services are actually single-page applications. This is starting with Gmail and ending with Google Photos. Many of these solutions are driven by JavaScript frameworks. Many of these frameworks are mentioned above. In Google’s case, this is Angular.

Software development is constantly evolving. The trend of creating single-page applications will grow with time. Surely, we can look work forward to search engine optimization by Google and other search engines. This would make using SSR not a necessity.

Differences between single-page applications and progressive web application

In recent years, talks about PWA applications have increased. It can be confusing, but the difference here is important. A PWA is really a set of “skills” that our single-page application can have. Using the right browser API, our application can behave almost exactly like a native application. It can have its own icon on the desktop, not use the browser address bar at all, or even send push notifications. Unfortunately, PWA applications are often limited by the incomplete support of some APIs. Also, the functionality and reliability of such applications leave much to be desired. Finally, they still give the impression that they are a web app.

Single-page app

Creating a single-page application on a native application level often requires a lot of work. It requires as much work as when creating a native application. Of course, there are solutions that work great and are hard to distinguish from native ones – for example, Linear or desktop Todoist. The advantage is a uniform code base and no need to create separate solutions for different operating systems. There is even an operating system that relies almost entirely on single-page applications – Chrome OS. Google is behind it, so that shouldn’t be surprising. However, it hasn’t gained much popularity outside the education sector in the US.

A traditional website may have some characteristics of a PWA. However, it will never gain all of its features due to the limitations of the architecture. Simply put, full-stack solutions are not able to utilize 100% of the PWA potential. Single page application architecture allows us to achieve all features of PWA. The only blocker remains the limitations of browsers. Therefore, if we are considering a PWA application it would be best to make it a single-page application.

Building web applications

The market is full of solutions to build a single-page application. In fact, there are no huge differences between frameworks when it comes to the end result. Each framework is better in some aspects than the other. The one you choose will depend on your individual needs. All of them use the same language – JavaScript. Each allows us to achieve great end results on both desktop and mobile devices. We will surely touch on important differences between these solutions from the programmer’s point of view. Also, how this can influence the final product.

As you may have already noticed, single-page application development is not such a simple matter. There are a lot of options and more issues to pay attention to. Fortunately, there are people who deal with such matters on a daily basis. They are willing to help you decide and implement the project so that it meets all your expectations. We hope this post was helpful to you and cleared up any doubts you may have had. We will certainly come back to the topic of single-page applications on our blog more than once, so keep your hand on the pulse!

Single page application development

If you are curious about having your own single page application, 👉 contact us 👈