SPA vs MPA: What's Best for Your Project?

The point isn't whether to create an application or not, it’s how to develop it  © (from a conversation between a manager and a client)

When building a web application, the most challenging decision is choosing the approach to its development. And here's the spoiler alert: there's no perfect solution. There's one that will effectively meet the specific business needs of the project.

But there's some good news. Developers have only two main types of architecture in their arsenal: Multi-Page Application (MPA) and Single-Page Application (SPA). So, theoretically, it will be easy to choose.

Those who are into web development, might argue at this point: "What about Progressively Enhanced Multi-Page App (PEMPA) or Progressive Web Application (PWA)?" - the concept that combines the advantages of MPA and SPA. In this article, we won't separate PEMPA (PWA) into a distinct section. It's a separate service and a broad topic for discussion. We'll delve into it further next time if there's interest from readers.

So, "Multi-Page Application or Single-Page Application (SPA)?" is a rhetorical question. Continuous debates (sometimes fierce battles) about this topic rage online all the time. This prompted us to organize the information and provide an objective answer. Read on to make the right decision for your project. Let's start, as usual, with the theory.

What Is a Multi-Page Application (MPA)? 

MPA architecture emerged alongside the first static websites, accompanying the early development of web technologies.

How it works:

1. A user inputs a request/URL in the address bar.
2. The browser sends an HTTP request to the server.
3.  The server processes the request and sends back HTML code, CSS styles, JavaScript scripts, etc.
4. The browser receives the necessary resources and displays the page to the user.

This "request-response" cycle repeats each time a user navigates between application pages. Actions occur both on the client side (in the user's browser) and on the server side, where necessary data is retrieved from storage and sent to the browser after rendering. Two-way communication enables the creation of powerful web applications.

In the early days of the Internet, when loading HTML code took considerable time, users rarely received feedback on the pending state. Then came the first indicators, one of the oldest being alternating symbols like \ | /—

Nowadays, for this purpose we use various animated Splash Screens and other preloaders.

For example, when you’re waiting for a video to load on YouTube, you’re shown a loader (spinner-circle).

Advantages of Multi-Page Application (MPA)

The main value of MPA lies in its simplicity of mental modeling. As a result, that influences development costs. That’s why MPA is often chosen for e-commerce niches and for creating large online platforms. Thanks to this architecture, we have such multi-page application examples as Amazon, Booking, LinkedIn, and even YouTube.

• MPA is better for SEO. By choosing a Multi-Page Application, you can potentially attract more traffic. Each page in MPA is independently ranked in search results because it has a unique URL.
• Security. Since MPA sends separate requests for each page, it’s easier to implement security measures such as authentication and authorization.
• Functionality. If one page of the application isn't working or has issues, the other pages can continue to function in a normal way.
• Scalability Opportunities. MPAs let us add an unlimited number of new features, product pages, service information, and so on.
• Lots of Ready-Made Solutions. Most web pages are multi-page applications, so no wonder that thousands of frameworks have been created for them. This also simplifies development complexity, increases speed, and reduces costs.

MPA Drawbacks

The main drawback of Multi-Page Application is considered to be low loading speed. We would argue against such a statement. At least during initial loading, MPAs often load faster. After all, the browser only needs to load the data of the current page, not all the content of the entire application. However, SPA typically shows higher performance afterwards.

To resolve the speed issue, it's important to choose a good server - then the loading time won't affect the user experience.

1. Limited Interactivity. Due to the need for full page reloads with each action, there are delays in the application's response, leading to a less smooth transition. Imagine if the page refreshed every time you liked a post on Twitter.
2. Tight Connection between Frontend and Backend. They cannot be developed in parallel; frameworks need to be used on both the client and server sides. In some MPAs, it may be challenging to implement familiar User Experience (UX).

Overall, MPAs remain a useful option for certain types of web applications (especially for e-commerce niches), particularly if SEO and fault tolerance are important.

What Is a Single-Page Application (SPA)?

The basic principles of this architecture emerged in the early 2000s, but the popularity of single page application development only surged in the 2010s. This was due to the emergence of new frameworks: React, Angular, Vue (and the desire to eliminate clumsy page loading).

The process of SPA operation looks as follows:

1. Application Loading: Upon the user's initial request, the browser loads the main HTML page, along with CSS styles and JavaScript scripts that comprise the application.
2. Execution of JavaScript Code: Initialization involves creating interface components, defining routes (routing), and other necessary actions.
3. Dynamic Updates using AJAX and client-side JavaScript.

Some of the most well-known Single-Page Applications include Gmail, Facebook, and Netflix.

We got rid of duplicated code by removing the User Interface (UI) side on the server, resulting in a smoother user experience and other benefits.

• Increased Performance. All resources are loaded within one session. Clicking links, submitting forms, scrolling the page—users receive data changes rather than a full page reload.
• Data Caching. Meaning the ability to work offline. This provides a better user experience when there's no internet connection.
• Simple Code Organization. Creating an application only requires a file://URL; you can even skip using a server.

SPA Drawbacks

In our view, the main downside of Single-Page Applications is the inability to achieve quality SEO optimization. But there are other drawbacks.

1. Browser Overload. Client-side frameworks are quite heavy. Large SPAs consume a lot of memory due to prolonged operation and accumulation of unused resources. Additionally, such applications may be incompatible with older browsers, limiting the potential user base.
2. Vulnerability. SPAs are susceptible to XSS (Cross-Site Scripting) attacks. It’s necessary to use input and output data filtering to avoid memory leaks.
3. Initial Loading Time. Especially if the application is large and requires many resources. This can be problematic for users with slow connections and those using outdated devices.

How To Choose Between SPAs and MPAs

It may sound cliché, but the choice between Single Page Applications (SPA) and Multi-Page Applications (MPA) depends on the specific needs of your project, its characteristics, and its goals. Let's express a subjective view on this matter.

MPA will be a fail-safe option for ecommerce development for projects that need to present a wide range of services/products. Such architecture makes it possible to create an unlimited number of features, pages, and menus. Your product will be successfully (and relatively cheaply) promoted in search engines (with SEO).

On the other hand, Single-Page Application architecture SPA has very reactive behavior and will be the best solution for creating platforms such as social networks, SaaS solutions, and closed communities, where SEO has little influence.

Opinions of Our Agile Team experts

For me, the contentious point is that SPA cannot be promoted for SEO. Every day, Google's search bots become smarter, and they can indeed index SPA applications. But personally, choosing SPA architecture for projects where SEO is important is like digging the ground with an ax. In theory, it's possible. But why, when there's a shovel? © SEO Specialist at Wezom

I used to believe for a long time that SPA architecture helps improve performance. But when we started working on a cross-platform mobile app for Miastoria Restaurant, I immediately offered MPA. The logic is simple: what used to be performed on powerful servers cannot quickly be executed on users' mini-computers. © Technical Product Owner at Wezom

(Note: You can view the full case study and discover more interesting solutions our team proposed for an online restaurant.)

I prefer the "classic approach," and in most cases, I insist on choosing a Multi-Page Application when we brainstorm. We have established processes, which greatly reduces development time. For example, if we were to make WT Group's Global Real Estate Platform as a Single-Page Application, it would take three times longer. © Middle Software Engineer at Wezom