We’ve all interacted with single-page applications and have found the experience to be a refreshing change of pace from traditional multi-page browser-based apps. Think Gmail, Netflix, PayPal, Facebook, Instagram – these are just some household examples of single-page applications and they all have two things in common – they are built to be functional and extremely fast.
Single-page applications are designed for speed, particularly after the initial load time, with minimal page reload time.
The most commonly used frameworks include Knockout.js, Angular.js, Ember.js, and Meteor.js. The primary goal of single-page applications is to increase engagement time. Research shows that application speed directly correlates to bounce rates and other engagement metrics. Single-page applications are designed to retain the user as long as necessary to provide a satisfying experience.
Exploring a Few Examples of Single Page Applications
Some of the most notable examples of single-page applications include Google Web Services and Twitter:
- Google Web Services
We’ve all used Google applications like Gmail, Calendar, and Google Drive. They’re all examples of single-page applications. Notice the progress bar loading on the screen when a Gmail app fires up? This is an indication that the app is fetching the required data from the server. The same applies to other Google applications. - Twitter
Twitter is a high-profile example of a single-page app, and arguably, one of the pioneers of the single-page application movement. The simple, clutter-free interface allows for maximum content consumption with surprisingly few clicks or other user-controlled behaviors.
Key Benefits of Single Page Applications
For the most part, single-page applications are ideal for dynamic pages with low volume data. Let’s take a look at some of the key benefits.
1. Faster Loading Time
Single-page applications load content much quicker than multi-page apps. This key benefit can’t be understated. The rise of high-speed internet has only decreased user patience. Users who may have previously blamed a website’s performance on a lagging connection speed now know that if the app they’re using isn’t performing well, the culprit is most likely the site itself.
To accomplish this, single-page applications connect to the server in small batches, which allows the server and user to save on precious bandwidth. Single-page apps request JSON data to dynamically update the user screen. This leads to less data being transferred at a time, freeing up bandwidth and reducing network traffic.
2. Easier Debugging
Instead of having to go through thousands of lines of server-side code, developers can troubleshoot problems with single-page applications by inspecting the JavaScript code rendered in a browser. Most JavaScript frameworks have debugging tools on Google Chrome for easy access. These tools reveal how certain pages are loaded, how pages request data, and how they cache information.
3. Easily Transition to Mobile Apps
Because all of the data is delivered at once, single-page applications are more suited for scrolling, which makes them an ideal starting point to develop mobile apps.
Common Problems with Single Page Apps
Single-page applications are not without their disadvantages. These include, but are not limited to:
1. Lower Initial Load Times
Because single-page applications load an entire application at once, the initial load time can take much longer for users. Actual loading times depend on how complex and efficient the JavaScript code is, but the setup can be taxing on both the server as well as the user during the initial download.
2. Difficulty of Coding
While it is easy to debug single-page applications, building one can be more challenging for developers lacking experience. Moreover, single-page apps are more likely to use various APIs and third-party plugins. This makes it more difficult to properly code and conduct diagnostics.
3. SEO
Though single-page applications are loved by users and developers alike, there’s no question that one of the key areas in which they frequently under-perform multi-page sites is in the area of search engine optimization. Ask yourself – when was the last time you clicked on a link that delivered you to Facebook, Twitter or a Google Calendar? Likely, the answer is never.
Clearly, there are technical reasons for this. Search engines find it harder to crawl single-page applications because their crawlers aren’t very efficient with Javascript-based apps. Google has rolled out new updates to increase single-page app SEO – but developers have to first make sure their JavaScript files are search engine-friendly.
At the same time, it’s also true that the use-case for single-page applications means that optimizing for SEO often isn’t a high priority.
This being the case, those considering launching a new application should give careful thought to the strategy that will be employed to attract new users to your platform. After all, traditional websites often attract half of their audience or more via search.
While there are a few popular work-arounds for optimizing SEO with single-page applications, each has their drawbacks.
For instance, some practitioners will opt to pre-render the content, offering up an HTML static page for search engines. While fine in theory, this strategy quickly falls apart with sites that change content frequently, particularly if such content is user-generated. Keeping in mind that some of the most popular single-page applications are all about user-generated content creation, the disconnect is obvious.
Server-side rendering is a more popular method of handling the challenge. With server-side rendering, a page is rendered by the web server as part of the server request/response cycle. When server-side rendering, the single-page app is rendered against a virtual DOM. In turn, that gets converted to an HTML string, which gets included in the page before it’s displayed for the user.
That said, the code rendered must work both in the browser and the server-based JavaScript environment. The single-page app will run each request to the server, thus making it run slower, which adds to the page load time.
In doing so, you’ve improved SEO, yet have hurt speed, arguably the top benefit of having a single-page application in the first place.
Single-Page Applications: In Conclusion
Today, single-page applications have found their place. Those seeking the fastest, lightest code deployments possible seek out these single-page apps as a way to keep users actively engaged on their websites.
At the same time, users would be wise to consider both the complexity of their application and the strategy needed to draw in users. The answers to these two questions will be the key determinants in whether or not a single-page application is right for your use case.
