Published on December 18, 2023

How to Optimize Single-Page Applications (SPAs) for Crawling and Indexing

How to Optimize Single-Page Applications (SPAs) for Crawling and Indexing

Single-page applications (SPAs) have become popular in recent years, and for good reason. They help companies deliver seamless web apps with interactive user experiences. Some examples of popular single-page applications include Netflix, Gmail, Airbnb, and Facebook.

JavaScript drives SPAs, and this presents unique challenges for search engine visibility. While the JS dynamic content is great for creating an interactive website experience, it causes crawling and indexing issues and can hurt organic traffic when not properly managed. In a way, SPA is a double-edged sword with a render SEO problem.

In this blog post, we will explore what single-page applications are, why they cause JavaScript SEO issues, and how to optimize SPA for crawling and indexing

What is a Single Page Application (SPA)?

A single page application (SPA) is a JavaScript-based web application that dynamically updates an existing page, as opposed to fetching complete new pages from the server. Think of SPA as a big container that houses all your content. 

This means that unlike traditional applications (websites) that store separate pages as distinct HTML files, SPAs utilize one single-page template to render dynamic web pages through AJAX calls. Hence, the name single page application.

This design eliminates the need for additional page loads after the initial loading process, contributing to a more seamless and responsive user experience (UX) and faster page loading time. That said, SPAs also pose some JavaScript SEO issues.

Why SPAs Cause JavaScript SEO Problems

SPAs are great for UX, but in the same vein, they’re not compatible with search engine indexing process. For a search engine to crawl a page, it must first discover the page, render and crawl the content to understand it, and then index it. 

Pro tip: Learn how Google and other search engines index JavaScript pages in this blog.

The problem with SPA indexing is that SPAs only display page content and elements through a dynamic API call. This means crawlers only see an empty container when they visit SPAs. And without any content to crawl, there’s nothing to index, and your page won’t show up on Google SERPs.

Here is what an SPA page looks like from the user side:

Example of a Single Page Application

Here’s what Googlebot would see when accessing the page:

Example of SPA from Google's perspective

While SPAs have significant benefits, they won’t bring you traffic if you don’t know how to optimize SPA. Luckily, we’re here to show you exactly how to make the SPA pages 100% crawled and indexed.

How to Optimize SPA for Perfect Indexation

1. Server-Side Rendering (SSR)

Server-side rendering (SSR) refers to a rendering technique where all the rendering process happens on the server before sending it to the client (browser). How does this affect SPA websites in terms of crawling and indexing?

With SSR, SPAs will render the JavaScript files on the server. When search engine crawlers request a page, the content is passed to the browser and reads as a fully rendered static HTML page. This results in a much faster loading time, as well as faster crawling and indexing time. And since the browser gets the content quicker, your rankings will also be boosted.

However, while SSR is a great way to optimize single-page application websites, there’s a significant reason why it’s not widely used: it’s expensive and difficult to implement. For SSR to work, you must invest around $120k upfront in servers, engineering hours, and expertise. Then there’s still the problem of scalability and maintenance. SSR may be a good way to optimize SPA, but it’s not a fix-all solution.

2. Implement SEO-friendly URLs

Another technique on how to optimize SPAs is implementing SEO-friendly URLs. This method provides search engine crawlers with clear paths by offering a structured and easily navigable hierarchy. Because of this, the crawling process is streamlined, ensuring that search engines can efficiently explore all elements of your single-page application website.

To create SEO-friendly URLs, it is fundamental to set up your URL router properly. If your router operates in hash mode, it appends #hash fragments to your home page URL. This will cause crawlers to ignore different app views of your SPA because the crawlers see hashed URLs as different parts of the same page. 

To achieve clean and SEO-friendly URLs while mitigating the risk of 404 errors, it’s essential to establish a fallback route on your server. This route redirects requests to your index.html page, where your app resides. Although this involves additional steps, popular JavaScript frameworks and libraries offer options for implementing this redirect.

A common mistake some SPAs make is using a single URL for everything on the app. This is a bad practice. When there’s just a single URL for everything, crawlers only see the home page and will not understand what the whole site is about. Therefore, you must treat views as URLs and change the URL anytime the app view changes. 

3. Dynamic Rendering with Prerender

Dynamic rendering is a technique used to serve different versions of a web page depending on the user agent requesting it (crawlers or human users). The system will provide static HTML for search engine bots and dynamic JavaScript content for human users. One of the prerendering solutions available in the market is Prerender.

Since Prerender rendered the content in advance, this JavaScript SEO tool is able to deliver your pages within 0.03 seconds on average, dramatically improving your server response time. Additionally, it renders other SEO benefits, including improved crawl budget management and website visibility. This blog will tell you about how Prerender works and its positive impact on your JavaScript SEO.

Related: Learn about what a crawl budget is and how to allocate it for indexing specific content only.

Solve Your Single Page Application SEO Problems With Prerender

By eliminating the requests between the server and browser, SPAs can greatly enhance PageSpeed and UX. As the internet continues to evolve, SPAs will likely become one of the most popular types of web applications. 

We’ve gone over important tips for optimizing SPAs in this blog. While all three methods will yield significant SEO results, the most resource-efficient strategy is setting up a dynamic rendering system with Prerender. Not only does Prerender boost PageSpeed score and SERP rankings, but also helps with crawl budget optimization. Moreover, since Prerender is a plug-and-play JavaScript SEO solution, you only need to install the middleware to get it started. 

Sign up for Prerender now to get the most out of your single-page application website! 

If you’d like to learn more about SPAs and how they impact SEO, take a look at these resources:

Picture of Prerender


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