Table of Contents
- What is a Single-page Application?
- How Does a SPA Work?
- What are the Advantages of SPAs?
What is a Single-page Application?
A single-page application (SPA) is a type of web app or website that dynamically rewrites the current page rather than loading entire new pages from a server.
This approach offers a distinct user experience when compared to traditional multi-page applications. For those unfamiliar with the differences, here is a blog on single-page vs. multi-page applications that provides you comprehensive difference between single-page and multi-page applications.
SPAs work inside a browser and require no page reloads during use. This is achieved by the application requesting associated data independently and rendering web pages directly in the browser. As a result, SPAs perform much like desktop applications, providing a seamless user experience with no interruptions due to page reloading.
Examples of single-page applications include Google’s Gmail, Google Maps, Facebook, Twitter, GitHub’s Instant Search, and many other popular web apps.
How Does a Single-page Application Work?
Let’s understand the step-by-step process of a single-page application. Below is the image of how SPA works.
Let’s consider in detail how a single-page application (SPA) works by understanding the example of Gmail.
User makes an HTTP Request
You open your search engines like Chrome and type in “www.gmail.com” or click on a bookmarked link.
Browser sends HTTP Request to Server
Your browser sends an HTTP request to Gmail’s server for the requested URL.
Browser renders the SPA
SPA makes HTTP Requests to the API Server
Once Gmail is running, it will handle most user interactions by making HTTP requests to an API server. For example, when you click on an email to read it, Gmail makes a request to the server to get the content of that email.
API Server responds with JSON/XML data
The API server responds to Gmail’s requests by sending back data, typically in JSON format. This data contains the content of the email you clicked on.
SPA updates the UI
Gmail uses the data it received from the API server to update the user interface. The email content is displayed on your screen without the whole page elements needing to reload.
This process repeats every time you interact with Gmail. Whether you’re sending an email, deleting an email, moving an email to a folder, or any other action, Gmail updates the appropriate part of the page without needing to reload the entire new page. This gives you a smooth, seamless experience.
Want to develop a single-page application? Here is a comprehensive guide to developing a single-page application. From this blog, you will understand the steps, cost, and timeline to build a single-page app.
What are the Advantages of Single-page Applications?
Here are the top 5 advantages of single-page applications.
Improves User Experience
Single-page apps provide more fluid and responsive user interaction and experience similar to desktop applications. Since only parts of the page are updated, there are no disruptive full-page reloads, which makes the application feel smoother and faster.
Efficient Network Usage
Single-page apps optimize network operations by sending only data—not HTML—over the network. This approach significantly reduces the amount of bandwidth used, resulting in more efficient network operations overall. Consequently, this can make SPAs more responsive, particularly over slower network connections.
Provides Easy Debugging
Tools like Chrome Developer Tools allow developers to easily debug their applications, which can be a big advantage during development.
SPAs can utilize data streaming and cache server data, even from only one request, to serve it when the user is offline. This process significantly improves usability in scenarios with poor or no internet connection. Additionally, the cached data can even maintain a form of browser history offline, further enhancing the user experience.