Single Page Applications (SPAs) are excellent to offer an outstanding user experience. They offer speed, involve a streamlined development process, and consume fewer server resources.

No wonder they are becoming increasingly popular today. Tech giants like Google use Single Page Applications such as Gmail and Google Maps to delight the users.

So, if you are thinking of building an application, SPA can be a good choice based on your requirements of a faster, cross-platform compatible, and feature-rich app for your SaaS business, social network, and other use cases.

But what exactly is SPA?

Let’s discuss Single Page Applications, their pros and cons, and how to create them.

What are Single Page Applications?

A Single Page Application (SPA) is a single web page, website, or web application that works within a web browser and loads just a single document. It does not need page reloading during its usage, and most of its content remains the same while only some of it needs updating. When the content needs to be updated, the SPA does it through JavaScript APIs.

This way, users can view a website without loading the entire new page and data from the server. As a result, performance increases, and you feel like using a native application. It offers a more dynamic web experience to the users. SPAs help users be in a single, uncomplicated web space in easy, workable, and simple ways.

Examples of SPAs

Gmail, Facebook, Trello, Google Maps, etc., all are Single Page Applications that offer an outstanding user experience in the browser with no page reloading.

For instance, when you open your Gmail account, you can see nothing changes much during navigation. Its header and sidebar are the same in the inbox, and when a new email arrives, it reflects the change quickly by loading its content via JavaScript.

How do SPAs work?

The architecture of Single page applications is simple. It involves client-side and server-side rendering technologies.

Suppose you want to visit a specific web page. When you enter its address to request access from your browser, the browser sends this request to a server and comes with an HTML document in return.

Using a SPA, the server sends the HTML document only for the first request, and for subsequent requests, it sends JSON data. This means a SPA will rewrite the current page’s content and not reload the whole web page. Hence, no need to wait extra for reloading and faster performance. This capability makes a SPA behave like a native application.

A Single Page Application is different from multi-page applications (MPAs). The latter are web apps with multiple pages reloaded when a user requests new data.

Furthermore, SPAs can take a while to load at first but offer faster performance and smooth navigation after loading. MPAs can be comparatively slow and needs top-class internet, especially with graphical elements. Examples of MPAs can be Amazon and Google Docs.

What are the benefits of SPAs? 👍

Most resources, like HTML, JavaScript, and CSS that SPA needs, are loaded initially and don’t require reloading when in use. Only data transmission can change, which makes it highly responsive. Let’s find out what all benefits SPAs offer.

Better speed

Web applications must offer faster speed and not waste users’ time; otherwise, users can find other efficient venues. SPAs provide shorter response times as the entire page doesn’t have to reload and only the data changes in the requested content parts. Thus, the web app’s speed improves considerably.

Enhanced user experience

Better user experience is vital for the success of an application. Many reports suggest that users leave web pages that are slower and not easy to use. But with SPAs, users don’t have to wait again to reload the full content only to gain a portion of it. Instead, they can gain the requested information faster, which improves their experience using a SPA.

Efficient caching

A Single Page App can cache data efficiently as it sends a request to a server for one time only and then updates the other data. This way, it can use this data to function even when you are offline. If a user’s connectivity breaks, it can synchronize the local data with the server when the connection is established.

Simplified development

Developing a SPA is easier as the developers don’t need to spend more time writing code and rendering the web pages on a server. Instead, they can reuse the server-side code and decouple the SPA from the frontend user interface. It implies that frontend and backend teams can concentrate on their jobs without worries.

But how?

The frontend development becomes effortless in SPAs due to their decoupled architecture, where frontend display separates from backend services. As a business’s critical backend functionalities don’t change much, your customers can have a consistent experience using your application, registering by filling a form, etc. You can keep the same content as well, but change how it looks.

When the backend logic and data decouples from how it is presented, you turn the app into service, enabling the developers to create multiple frontend ways and show that service. It also lets developers build, experiment, and deploy the frontend without worrying about the backend technology.

Easy to debug

Debugging an application is vital to ensure nothing can stop it from performing optimally by detecting and removing bugs and errors that can slow down its performance.

Single Page Applications are easy to debug with Google Chrome as they are built using popular frameworks like React, Angular, Vue.js, etc. You can easily monitor and investigate page elements, data, and network operations.

In addition, debugging in SPA is easier than MPAs because SPAs have their own developer tools for Chrome. Developers can examine the JS code rendering from the browser and debug SPAs instead of going through hundreds and thousands of lines of code. The Chrome debugging tools also view page elements, data requests from the server, and data caching.

Less resource consumption

Single Page Apps consume less bandwidth as they load the pages just once. They also work in areas with a slower internet connection, hence, convenient to use for everyone. Besides, they work offline, saving your data, so you don’t have to supply them with consistent internet to access and work on them, unlike MPAs like Google Docs.

Cross-platform compatibility

Developers can build applications that can run on any operating system, device, and browser easily using a single codebase. Hence, it adds to customer experience as well because they can use the SPA anywhere they want.

In addition, developers can also build feature-rich apps quite effortlessly. For instance, they can include real-time analytics while developing a content editing application.

However, there are also some negatives associated with SPAs.

Disadvantages of SPAs 👎

Poor SEO performance 

The SPAs architecture involves just a single page with a single URL. It limits the SPAs’ ability to benefit from search engine optimization (SEO). SEO techniques help improve your site’s ranking in the search engine results, as there’s high competition out there.

As there is just a single URL with no changes or exceptional addresses, optimizing it for SEO is tricky. It lacks indexation, good analytics, unique links, metadata, etc. Such pages get tough luck to be scanned by the search bots, so optimization becomes difficult.

Online threats

SPAs are more vulnerable to online threats such as cross-site scripting (XSS) than MPAs. Attackers can utilize XSS to inject client-side scripts into a web app and compromise it. In addition, access control is not tight at the operational level. It can expose sensitive data and functions if the developers don’t take precautions.

Initial load times

Although SPAs are praised for showcasing great performance and speed, it takes a while to load the complete site. It may irritate some users who may not open the app again.

Browser history

SPAs don’t store browser history. If you check the history for any valuable data, you only see the SPA’s link to the entire website. Also, you can’t move back and forth in the SPA. If you press the back button, you end up on a previously loaded web page, not the previous state. However, this drawback can be neutralized by using the HTML5 History API.

When should you use SPAs?

SPAs come with a lot of benefits but also drawbacks, as you saw in the previous section. So, it’s not wise to say that it’s entirely good or bad. It depends upon your requirements and goals to create an application.

  • If you want to build a website with smaller data volumes and a dynamic platform, you can use single-page applications.
  • It’s also fruitful if you plan to build a mobile application in the future, you can use the backend API for both your site and mobile app.
  • SPAs architecture is also suitable to build social networks (for instance, Facebook), closed communities, and SaaS platforms as they don’t need much SEO.
  • If you wish to offer a seamless user interaction in your application, go for a SPA. Single Page Apps like Google Maps use this approach to provide live changes when users move from one place to another.
  • SPAs are also great if you want to offer live updates on your application for purposes like data streaming, real-time charts, notifications, alerts, etc.
  • Choose SPAs if you want to offer a native-like, consistent, and dynamic user experience across different operating systems, browsers, and devices.

So, if you tick any or some of the points mentioned above, you can go for SPAs. Let’s quickly understand how to create Single Page Applications.

How to create SPAs?

Any software development, including SPA, requires three most important aspects – a team, the time, and tools and technologies to produce the app.


You must have a development team with expertise in JavaScript, CSS, and HTML, along with knowledge of other related technologies. Build a team of:

  • Project managers to head the team and monitor and guide the development process
  • JavaScript developers to write quality frontend code
  • UX/UI designers to design the app beautifully while taking account of usability
  • Backend software engineers to connect the server and app’s interface seamlessly
  • QA specialists to test the application for errors and bugs, ensuring nothing can compromise the app performance

Time and budget

Fix a timeline of your app development to ensure it completes when you need it to deploy in the market. Determine the timeline according to the app’s complexity, feature requirements, and team size. Dedicate enough time to research, plan, and develop a streamlined process for each development stage, from writing code to designing, testing, and deployment.

In addition, have plans and resources for the app maintenance to resolve issues, add new features, update content, etc. Also, ensure everything works within your budget. For this, allocate your team members and resources smartly.

Tools and technologies

Tools and technologies are critical in web app development. As mentioned earlier, JavaScript, CSS, and HTML are three technologies you must employ to develop your SPA. Apart from that, you need a bunch of other tools as well, such as JavaScript frameworks to build the app’s “skeleton,” Ajax (JS and XML) for deployment, backend technologies like PHP, Node.js, etc., and a database like MongoDB or MySQL.

Let’s understand a bit more about JavaScript frameworks suitable for SPA development.


Ember or Ember.js is a great JavaScript framework to build a single-page application. It is productive and battle-tested to offer a solid base to create your application. It has the capabilities you need to create feature-rich user interfaces that work on multiple devices.

Ember’s UI architecture is scalable and has supported top global firms such as Microsoft, Apple, Netflix, LinkedIn, and more. It’s a “battery-included” framework with everything you would need to have an out-of-the-box experience from day one of your app development.

Ember CLI works like a backbone of the Ember application and seamlessly provides code generators to build new entities, arrange files, etc. It offers a built-in environment with fast auto-reloads, rebuilds, and test runs. You can also deploy your app quickly using a single command.

Furthermore, Ember’s router is excellent and includes asynchronized data loading, query parameters, and dynamic URLs. In addition, it has a fully-featured library for data access (known as Ember Data), comprehensive testing, and free performance upgrades.


One of the best JavaScript frameworks, Angular.js, helps you efficiently create your single-page application with robust capabilities. It allows you to extend your application’s HTML vocabulary and offers an environment that’s quick to build, readable, and expressive.

Angular.js is highly extensible and compatible with multiple libraries. You can also easily replace or modify any feature to customize your application and make it based on your feature needs and suit your development workflow.

Moreover, Angular.js employs data binding to update the view based on the model changes and removes DOM manipulation. You can also utilize controllers and plain JavaScript to help you easily maintain, test, and reuse your code.

You can create components with directives, reusable components, and localization. In addition, use deep linking, form validation, and enable efficient server communication using its capabilities.


Backend.js provides a sturdy “backbone” or structure to applications with models, custom events, key-value binding, views with event handling, and collections with multiple functions. It connects to your API using a RESTful JSON interface.

You can use its router to update your app’s browser URL and enable users to bookmark and share it. Its code is available on GitHub and has the MIT license. Some of the apps using Backbone.js are Hulu, Airbnb, Pandora, Trello, Stripe, Khan Academy, Bitbucket,, and more.


Vue.js is a progressive JS framework and offers a versatile ecosystem to help build your SPA. This MIT-licensed open-source project has made it possible to create an excellent user interface for Single Page Applications easily.

It is designed to be adaptable and can scale between a framework and library based on the use case. Its approachable library focuses only on the app’s view layer and offers libraries to handle complexities in larger single-page applications.


React is one of the most popular JavaScript libraries to create Single Page Applications. It’s developed and maintained by Facebook (now Meta) developers. And it’s open-source, you can contribute to it as well.

There are a lot of reasons to get pick React for developing your next SPA. Let’s see some of them.

  • Easily adaptable if you are a JavaScript developer.
  • React documentation is the best place to start learning it.
  • If you learn the concepts of React, it will help you to build mobile applications as well with React Native which follows similar concepts.
  • A large community that leads to a large set of third-party packages.
  • Most of the companies like Facebook, Bloomberg, Airbnb, Instagram, Skype, etc.., use React library to develop UI.

It’s not overwhelming to say that React is the most popular library to build web applications at the time. Give it a try you will love it. Check out these resources to learn React if needed.

Conclusion 👨‍💻

Single Page Applications (SPAs) can be helpful to you if you want to build a highly responsive, faster, and feature-rich application for social networking, SaaS business, live updates, etc. Thus, determine your requirements and goals to decide if a SPA will suit your development process and choose a JavaScript framework accordingly to get started.