A multi-page application is a website made up of many different sub-websites, or pages. When you interact with the site, new pages are downloaded from the server. A multi-page application really is what it says on the tin: an application made up of multiple pages. Historically, all webpages were multi-page applications (MPAs), but these days, there’s an alternative: single-page applications (SPAs). SPAs download their webpage only once from the server, then update the same page with new data in response to user interaction. Examples of Multi-Page Applications Any website you remember from the early days of the internet is a multi-page application - but plenty of modern websites are also MPAs. Some examples of MPAs include blogs, ecommerce sites, and online newspapers and magazines. Amazon, Wikipedia, and the website of The New York Times are all multi-page applications. How to Tell if a Website is an MPA On an intuitive level, if a site looks more like a website and less like a mobile app, it’s probably a multi-page application. Think old-school (like Wikipedia) rather than newfangled (like Twitter). Here’s a more precise test. If you click on an (internal) link on the website and the reload button next to the address bar in your browser becomes an X, the website is an MPA. The X means that the browser is downloading new pages from the server. Pros of Multi-Page Applications Despite the rise of single-page applications, multi-page applications remain the best choice for large apps such as e-commerce sites, which don’t lend themselves well to the linear structure of an SPA. Compared to SPAs, MPAs can have a faster initial load time. This is why it typically doesn’t make sense to make very large SPAs; preloading everything would simply take too long. It’s also much easier to make MPAs rank highly in searches; because the underlying HTML doesn’t reflect their content very well, SPAs have SEO issues. Google Analytics also works better with MPAs, allowing you to quickly tell which parts of your app users respond the most strongly to - and once again, helping your site rank highly in searches. Finally, MPAs have better compatibility with old browsers than SPAs, and don’t need to require JavaScript. Cons of Multi-Page Applications MPAs are typically slower than SPAs, at least after the initial load. Interruptions due to page loads make for a less smooth user experience. Because of their non-linear structure, MPAs can also be harder to navigate than SPAs. (This isn’t a problem for well-structured domains such as the categories in an online store, though.) Development and testing are harder for MPAs, because their frontend and backend are more tightly coupled. Such apps are also hard to maintain, because each page must be separately modified.