Single page applications (SPAs) and multi page applications (MPAs) are two major ways of building web applications. With rapid advancements in web development technology, the debate between SPAs and MPAs continues to grow in 2024. Both have their own sets of pros and cons for factors like performance, SEO, maintenance, and development effort.
What is a Single Page Application?
A single page application is a web application that loads a single web document and then updates the body content of that single document via like XMLHttp Request and Fetch when different actions are performed, without loading entire new pages from the server. This means much of the work is done client side via JavaScript running in the browser rather than server side.
Some key characteristics of SPAs:
- Only one page is loaded by the browser
- Navigation does not trigger page reloads, instead new data is dynamically loaded
- UI is updated via JavaScript by manipulating the DOM
- Fast performance due to minimized server requests after initial page load
Some examples of popular SPAs are Gmail, Google Maps, Facebook, and Twitter.
What is a Multi Page Application?
In contrast to SPAs, a multi page application loads entire new pages from the server each time navigation actions are taken. This means that MPAs rely more on server side processing and page reloads compared to heavy client-side JavaScript.
Some characteristics of traditional MPAs:
- Each navigation triggers a whole new page to be loaded from server
- More page reloads back and forth between client and server
- UI is generated server-side via templating engines
- Slower performance due to more frequent full page reloads
Examples of traditional multi page websites are old versions of Wikipedia, news websites, online forums sites, and content/brochure style sites.
However, modern MPAs have started incorporating JavaScript and AJAX as well for partial page updates. So the line between SPAs and MPAs is getting blurrier.
Key Differences Between SPAs and MPAs
Here is a table summarizing some of the key differences between single page and multi page applications:
| Aspect | Single Page Apps | Multi Page Apps |
|---|---|---|
| Page loads | Only initial page loaded | New pages loaded on every navigation |
| Processing | Mostly client-side | Mostly server-side |
| Navigation | JavaScript updates DOM without reload | Full page reload for every navigation |
| Performance | Very fast after initial load | Slower with more full page loads |
| SEO | More challenging | Easier |
| Hosting | Can be hosted on CDNs | Requires server-side hosting |
So in summary, SPAs minimize server requests after initial page load for very fast UIs, while MPAs have full page reloads for every navigation. Next, let’s do a deeper comparison between SPAs vs MPAs across some key considerations:
Performance Comparison
Performance is faster in SPAs primarily due to below factors:
- Only initial page is loaded fully further interactions just fetch required data.
- No page reloads between navigations once SPA loaded initially. Just DOM manipulations happen client-side.
- Lightweight as assets like HTML/CSS cached in browser. Just data flowing back & forth.
- Can use latest web standards like HTTP/2, Server Push CDNs for faster delivery.
In MPAs, every navigation triggers a full page reload along with fresh download of HTML, CSS, scripts etc. This results in slower performance with every interaction. However, latest MPAs using technologies like AJAX can emulate some SPA style partial updates for faster experience. But overall, SPAs have the edge performance wise.
SEO Comparison
SEO is more challenging for SPAs compared to MPAs. Some key SEO differences:
- Initial page serve vital for SPA SEO as crawler bots don’t execute JavaScript well.
- MPAs serve full pre-rendered HTML pages detectable by crawlers.
- solutions like server-side rendering, pre-rendering & snapshots help SPA SEO.
- But MPAs don’t need special efforts for SEO friendliness.
So for public-facing sites where SEO is vital, MPAs may work better. For web apps focused on user experience over SEO, SPAs make more sense.
Maintainability Comparison
Code maintenance differs as SPAs tend to have more complex JavaScript with most logic living in various scripts & modules. Having one single page also means scoped CSS can be trickier.
MPAs on the flipside have logic split across multiple simpler server-side files & routes. And with multiple pages, CSS maintenance is easier due to page specific scopes. So from legacy maintainability perspective, MPAs have some advantage. But for teams proficient in JavaScript, SPAs code maintenance is not very challenging comparatively.
Developer Experience Comparison
Developer experience can vary across teams. Those well versed in JavaScript/TypeScript may find building SPAs more enjoyable due to exclusively using one language without context switching. State management solutions like Redux also lend well to developer DX. For server-side developers, MPAs may feel more aligned to their mental models. Switching between different files & languages comes naturally. So developer experience really depends on the tech stack expertise of teams rather than a clear choice between SPA vs MPA.
Use Case Comparison
Some typical use cases better suited for SPAs are:
- Highly interactive complex web apps e.g. email, social networks
- Apps not dependent on SEO to acquire users
- Applications where latest UI standards are vital – e.g. games
- Real time collaborative apps with data syncing needs
Some use cases where MPAs work well:
- Marketing websites where SEO is very vital
- Simple company brochure sites for branding
- Quick marketing campaign microsites where speed matters over complexity
- Legacy systems where full transition has constraints
Of course, many modern web apps take a hybrid approach choosing SPA for some parts of the app and server-side multi pages for others. Ultimately the use case and priorities drive the technology choice.
Current SPA vs MPA Usage Statisics
According to various surveys on SPA usage and trends:
- ~60% developers used/using SPAs as per State of JavaScript 2019 survey
- ~80% sites use MPAs while ~15% have SPAs as per crawl data from Datanyze
- But SPA usage grew from ~6% to 15% from 2017 to 2022 as per Datanyze crawl
- As per SimilarWeb only ~2.2% sites were built as SPAs in 2019
So while MPAs still dominate the web currently in 2024, the gradual rise of SPAs is clear driven by user expectations of app like experiences demanding faster Web UIs. The lines between SPA vs MPA continue to blur with many sites taking a hybrid approach. And continued JavaScript performance improvements in browsers also contributes to SPA adoption uptrend.
The Road Ahead
- Modern web development is steadily moving towards JavaScript powered SPAs and MPAs incorporating latest web capabilities for performance.
- Server-side rendered SPAs strike a balance by allowing pre-rendering for SEO while having snappy JavaScript clients.
- Web development frameworks like Next.js (React), Nuxt (Vue) and SvelteKit make building such Universal JavaScript apps easier for the ahead road.
- Statically generated SPAs at build time using incremental regeneration also helps solve traditional downsides like SEO. Tools like Gatsby and Next.js enable such capabilities today.
- WebAssembly for near native speeds, Web Workers for multi threading, Web GPU for graphics/video acceleration etc continue to unlock new performance milestones ahead.
Choosing Between SPA and MPA
When choosing between building a single page application (SPA) and a traditional multi page application (MPA), consider these key criteria:
App Type
- SPA best for complex, interactive web apps e.g. dashboards, email
- MPA suitable for simple informational websites
Importance of SEO
- MPA easier to optimize for search engines
- SPA can work but needs special efforts
Target Users
- SPA provides richer experience for tech savvy mobile users
- MPA sufficient for users who briefly visit site
Development Team
- SPA if team has strong JavaScript skills
- MPA for server side focused teams
Budget & Timelines
- SPA requires more upfront development effort
- MPA faster & cheaper for simple sites
When in doubt, modern hybrid approaches can work well:
- Initial pages server rendered for SEO
- Switch to SPA after landing pages
- Have SPA style pages for logged in app experience
- Static site generation for some marketing pages
Hybrid Approaches Are Popular
Increasingly most major sites take a pragmatic hybrid approach choosing the best from SPA and MPA for each section. For example, Netflix uses server rendered React pages for marketing and authentication flows to allow SEO and resolve initial entry points.
But once logged in, it switches to a snappy React SPA UI for the actual video watching experience optimized for user experience over SEO needs. Stack Overflow uses ASP.NET Razor server rendered views for public question/answers pages to allow crawlers to index content.
But for logged in high frequency user actions like voting, commenting etc it switches to React with partial page updates for speed. This “progressive enhancement” approach starting with a server rendered baseline, then layering on modern UI tech gives the best of both worlds.
Initial entry points get SEO, link sharing etc while repeat visits provide a snappier experience. Code can also be shared between server and client for less duplication. So rather than SPA vs MPA, the pragmatic path is utilizing both approaches where ideal. Modern web frameworks make building such hybrid apps easier.
Conclusion
The debate between single page and multi page apps continues to evolve in tandem with web standards. For basic websites with heavy SEO needs, multi page server rendered apps may work best. For complex web applications focused on user experience over SEO, modern JavaScript powered single page applications are ideal. But increasingly developers are taking a pragmatic hybrid approach choosing SPA or MPA on a per use case basis. With performance of JavaScript runtimes and web capabilities improving further, rich single page application experiences are likely to gain more dominance in future dynamic webapps. Yet static multi page content sites will continue to retain value. The future is likely a blend of SPA, MPA and mixed hybrid approaches suiting specific functional needs.
Frequently Asked Questions
Is SPA or MPA better for SEO?
MPA is generally easier to optimize for SEO as content is server rendered and easily crawlable. SPA needs special efforts like pre-rendering for good SEO.
Which is better for complex web applications?
SPA is better suited for building highly interactive complex web applications due to faster performance powered by client side JavaScript.
What is the difference between SPA and MPA?
Key differences are SPA loads initial page and updates views without full page loads while MPA has page refreshes with every navigation. SPA is heavier on client side JavaScript while MPA relies more on server side processing.
Is SPA or MPA faster?
SPA delivers extremely fast performance after initial load by minimizing server requests. MPA is slower comparatively due to frequent full page refreshes with every user action.
Should I choose SPA or MPA for my next project
Choose based on app type, SEO needs, target users, team skills, timelines and complexity. Often a hybrid approach works taking the best from SPA and MPA per section.
