Single Page Application (SPA) vs Multi Page Application (MPA): Which Is The Best?
There are two main architecture options for building web applications: single page applications (SPAs) and multi-page applications (MPAs). Single page applications work within a single browser session and allow users to jump between parts of the system without requiring the entire page to reload. On the other hand, multi-page applications require a new page to be loaded every time the user interacts with the application. It's important to note that SPAs are typically faster and provide a more seamless user experience, while MPAs may be more suitable for certain types of content, such as blogs or news websites.
SPAs started to become popular around the mid 2010’s with the arrival of frameworks like React, Angular and Vue. The reason they took off boiled down to one thing; removing the clunky page load event.
Think of how Facebook, Twitter and Instagram allow users to continually scroll through a main feed. This is the magic behind SPAs. If these platforms operated as a multi-page application, users would need to refresh their page every time the feed ran out, interrupting the experience.
Even though the big social media companies have thrown their weight behind SPA architecture, it’s not a magic bullet that is a great fit for every application. There’s plenty of massive companies that run multi-page applications because it makes more sense.
In this post, we will look in-depth at the difference between SPAs and MPAs. Our goal is to provide a comprehensive comparison of these two approaches and provide practical advice for choosing the right architecture for your web application.
Understanding single page applications
SPAs are web applications that dynamically update their content as users interact with it. They don’t require page reloads thanks to AJAX (Asynchronous JavaScript and XML) which allows web applications to communicate with a server in the background without interfering with the behavior of the page. When a user interacts with a SPA, only the required component will be modified and not the entire page/application. As a result, SPAs offer high performance and a nice user experience.
The best way to understand the concept of a SPA is to contrast it against how traditional web applications. Each time a user interacts with the application, the browser sends a request to the server. The server then sends back a new HTML page.
With SPAs, the browser loads a single HTML page and then leverages JavaScript to dynamically update the content of that page as the user interacts with it.
As a result, SPAs provide a seamless user experience as they appear to load faster and offer better performance. Some of the most popular SPAs include; Google Maps, Gmail, Trello, Twitter, and Facebook.
Advantages of SPAs
Below are some of the key benefits of SPAs:
Faster loading times
SPAs only load the necessary components once, and subsequent page updates are made dynamically without requiring a full page reload. This results in faster page loading times and a smoother user experience.
Great user experience
SPAs provide a more responsive and interactive user experience, with no lag or interruptions when navigating between pages or sections. The dynamic updating of the page elements makes for a seamless experience.
This kind of experience has become expected in some applications (like social media), and it's honestly pretty great. It's not always practical, but from a user perspective, it's a winner.
Easier to maintain and scale
SPAs are easier to maintain because they use a modular design, where each component is responsible for its functionality. This makes it easier to modify or replace components without impacting other parts of the application. Additionally, SPAs can be scaled more efficiently by adding more servers to handle the load.
Offline functionality
Offline functionality in SPAs is achieved by implementing service workers. These are basically scripts that run in the background of the user's browser, intercepting and caching network requests. When the user is offline, the SPA can display a cached version of the website so that the user can continue to use the application even when there is no internet connection. When the user goes back online, the service worker can sync any changes made while offline with the server.
This benefit verges into the Progressive Web Application territory, which we've written about extensively, so we don't repeat too much of the content.
Offline functionality helps improve user experience by allowing users to continue working with the application even when they lose their internet connection.
Reduced server load
Server requests are minimized because the application uses APIs to retrieve data from the server rather than requiring the server to generate an entire page for each request.
Decoupled frontend and backend
SPAs are designed to work with APIs that facilitate communication between the backend and frontend. This decoupling allows developers to change one without impacting the other, resulting in a more modular, flexible, and maintainable codebase.
Decoupling the backend and frontend also allows for better collaboration between developers working on different parts of the application. For example, the backend developers can work on the API, while the frontend developers can work on the user interface, without interfering with each other.
Disadvantages of SPAs
Despite their advantages, SPAs have their own fair share of disadvantages. These include:
Initial load time
Since SPAs load all their content simultaneously, they can take longer to load initially. This can be a problem for users with slow internet connections or older devices.
Offer poor SEO
Traditionally, SPAs have been difficult to optimize for search engines because they typically have only one URL and limited content on the initial page load, which affects their search engine ranking.
We've thrown this disadvantage into the list even though it's becoming moot in 2023. Every day Google becomes smarter and it's well-known that its engine can index SPAs. Despite this, it's probably safe to argue that MPAs are quicker to index than SPAs when new.
Browser compatibility issues
SPAs may not be compatible with older browsers or devices, which can limit the potential user base.
This is another half-hearted disadvantage. Internet Explorer is no longer supported, and it was one of the problem browsers that struggled with SPAs. Older versions of Safari as also hit-and-miss, but the percentage of users that actively use this browser version is low.
Memory leaks
Security leaks are a potential disadvantage of Single Page Applications (SPAs) due to the heavy reliance on JavaScript. Because most application logic is executed on the client side, it can be more vulnerable to certain types of attacks like cross-site scripting (XSS) or cross-site request forgery (CSRF) attacks.
XSS attacks occur when an attacker injects malicious code into the SPA, which is then executed on the user's browser. This can lead to the theft of sensitive information like user credentials or session tokens. To prevent XSS attacks, it's important to properly validate and sanitize user input, as well as implement other security measures like Content Security Policy (CSP) and Cross-Site Request Forgery (CSRF) protection.
Understanding multi-page applications
As the name suggests, multi-page applications are web applications that consist of a large number of HTML pages. Each page displays different content that has to be refreshed each time a user interacts with it.
MPAs have been around since the early days of the web and are still widely used today. They are especially common in content-heavy websites, such as news sites or e-commerce sites, where each page represents a different piece of content or product.
Some of the most popular MPAs include; Amazon, The New York Times, Wikipedia, and eBay.
Advantages of MPAs
Here are some of the advantages of MPAs:
Better for SEO
MPAs tend to rank well in search engine results since each page has a unique URL and can be indexed separately. This means that each page in an MPA can rank independently in search results, potentially driving more traffic to the site.
As we mentioned in the SPA section, this is more of an issue for young applications. Once a SPA receives hundreds of thousands of views a month, it becomes irrelevant because Google will prioritize the reindexing of the app.
Secure
Since MPAs send separate requests for each page, it is easier to implement security measures such as authentication and authorization. In contrast, SPAs can be more vulnerable to security threats since much of the content is loaded dynamically and may not be subject to the same security checks as traditional web pages.
Faster initial load time
While SPAs offer better performance once the initial page has loaded, the initial load time of an MPA is often faster since the browser only needs to load the content for the current page rather than all the content for the entire application.
Compatible with older browsers
MPA is a classic way of building web pages, so it's compatible with most older browsers and legacy systems. This compatibility is important in situations where users may be accessing the application from a variety of devices or platforms.
Disadvantages of MPAs
Here are some of the disadvantages of MPAs:
Outperformed by SPAs
Since MPAs require a full page reload when a user interacts with the app, they offer poor performance, which negatively impacts the user experience.
Complex to develop and maintain
MPAs are larger than SPAs and as such, take more time to develop since they consist of multiple pages. Also, MPAs require more complex server-side logic compared to SPAs, as each page needs to be designed and developed separately. This can result in more code to maintain and a higher risk of bugs and errors.
Higher server load
MPAs require the server to handle more requests, as each page requires a separate request to load. This can lead to higher server load and slower response times, especially for applications with a large number of users.
SPAs vs MPAs: Which one should you choose?
Ideally, SPAs are used to build dynamic platforms with small data volumes, while MPAs are best suited for large applications with high-volume data. But there’s more to choosing between the two than just considering the amount of data your app will handle. Here are some more crucial factors to keep in mind:
Complexity of your application
SPAs are well-suited for complex applications that require a high level of interactivity and real-time updates. They can be particularly useful for applications with a lot of user input or content that needs to be updated frequently. With a SPA, users can interact with the application without needing page refreshes, providing a more seamless experience.
On the other hand, MPAs may be a better choice for simpler applications that do not require as much client-side processing. In an MPA, each page is separate, which can make it easier to manage and navigate for smaller applications. If your application is relatively simple and does not require a high degree of interactivity or real-time updates, then an MPA may be a better choice.
Performance requirements
If performance is a top priority for your application, then SPAs may be the way to go. SPAs are designed to load content dynamically without requiring a full page refresh. This means that users can interact with the application more quickly and efficiently. Additionally, SPAs can reduce server load, which can improve overall performance.
However, MPAs may be better suited for applications that require fast initial load times, as well as applications that rely heavily on caching to improve performance. Each page in an MPA is separate, which means that they can be cached independently. This can help to improve load times and reduce server load, particularly for static content.
SEO requirements
As a business owner, you probably want your app to rank high on search engines to increase brand visibility and conversion rate. You can achieve this with an MPA since each page has its own unique URL, title, and metadata, making it easier for search engines to index the content and rank it accordingly.
Nonetheless, SPAs can be optimized for search engines. But it requires additional effort and knowledge of SEO best practices, such as using hashbang URLs, implementing server-side rendering, and making use of metadata tags. If you are willing to put in the extra effort, then a SPA can still be an excellent choice for an application that requires SEO.
Time to market
SPAs are easier and faster to build and as such, enable businesses to launch their products faster. MPAs tend to take a lot of time and even cost more since they involve building multiple pages. However, SPAs rely heavily on advanced JavaScript frameworks and tools, so you might have a problem finding the right talent to build your SPA.
Frequently asked questions
Q: What exactly is a single page application (SPA)?
A: A single page application (SPA) is a web application that loads a single HTML page and dynamically updates the content as the user interacts with the application. SPAs typically rely heavily on JavaScript frameworks such as React, Angular, and Vue to manage the application state and user interface.
Q: What is a multi page application (MPA) and how does it differ from an SPA?
A: A multi page application (MPA) is a traditional web application that loads multiple HTML pages as the user navigates through the application. Unlike a SPA, each page in an MPA is separate and requires a full page refresh to update the content.
Q: Can SPAs be used for any type of website or application?
A: While SPAs can be used for any type of website or application, they are best suited for applications that require a high degree of interactivity and real-time updates, such as social media platforms or productivity tools.
Key Takeaway
Ultimately, the choice between a SPA and an MPA should be based on the specific needs and requirements of your application. If your application requires a high degree of interactivity and real-time updates, then a SPA may be the better choice despite the added complexity. However, if your application is relatively simple and does not require a lot of client-side processing, then an MPA may be the simpler and more practical choice.
