Published on January 26, 2024

How to Fix 404 Errors on SPAs

Have you ever encountered a 404 error while browsing the web?

404 errors signal that a requested page is not found, a common error for single-page applications (SPAs). While there are a couple of traditional solutions to fix error 404, they often fall short due to the intricate nature of SPAs. Left untreated, 404 errors can frustrate users when accessing your page and damage your brand’s reputation.

This article will provide a comprehensive understanding of 404 errors on SPAs. We’ll start with understanding what a 404 error is and what causes it, then introduce you to a powerful solution that fixes error 404 effectively.

What is a 404 Error?

Before we dive into the specifics of 404 errors on SPAs, let’s understand the concept of 404 errors.

Essentially, a 404 error is an HTTP status code that indicates the server could not find the requested webpage. That’s why some called the 404 error ‘404 page not found.’  

A 404 page not found error occurs for various reasons, such as mistyped URLs, broken links, or deleted content. Developers often create custom 404 pages by adding links to other pages, writing apology messages, or even turning them into humorous messages to reduce the impact on user experience.

Is a 404 Error the Same as a Soft 404 Error?

While a 404 page not found error is pretty straightforward, developers often encounter a more complicated variant known as a soft 404. A soft 404 error occurs when a server returns a 200 OK status code instead of a 404 error code, even though it’s an empty page or a page that doesn’t exist.

Although soft 404 SEO errors are not among the “official” SEO HTML status codes, they are common and can harm the SEO performance of single-page applications. When search engine bots try to crawl a page with soft 404 and get a 200 OK status code, it indicates that the page exists and will continue to crawl the page—wasting your limited crawl budget.

And since the page or some of its content is missing, the search engine may index an empty page with nothing to display on search results. This will waste your hard work and valuable SEO elements and ruin your user experience. 

Understanding 404 Errors on SPAs

SPAs built with JavaScript and its frameworks have gained popularity over the years. They deliver fluid, app-like experiences within browsers, enabling websites to load content dynamically. However, it also comes with drawbacks, namely challenges in handling URLs and responding to requests.

In a single page load, a SPA retrieves all necessary HTML, CSS, and JavaScript code, updating the content without requiring a full page refresh. This approach enhances user interaction and engagement but introduces complexities in managing URLs, especially when users navigate between different application sections.

Furthermore, unlike traditional multi-page applications, SPAs render JavaScript on the client side. This means that JavaScript manages navigation, interprets the URL changes, and fetches the necessary content without making a server request. While this enhances speed and responsiveness, it also means that the server may not be aware of all possible routes, eventually leading to 404 errors.

Some Common Causes of 404 Errors on SPAs

  • JavaScript-based navigation challenges
    SPAs heavily depend on JavaScript for navigation. If JavaScript fails to load or execute routes properly, users may encounter 404 errors. This is because the client-side routing is unable to interpret and handle the URL changes.
  • SEO HTML status codes and their implications
    Search engine crawlers may struggle to index SPAs due to the dynamic nature of the content loading. This can lead to search engines encountering 404 errors when attempting to crawl pages that haven’t been rendered or properly configured.
  • Crawling and indexing issues
    Search engine crawlers, which traditionally rely on static HTML content, may not effectively navigate SPAs before ranking their pages. This results in 404 errors for users accessing those pages via search results.

Related: Learn how to optimize SPAs for crawling and indexing here.

5 Methods to Resolve 404 Errors on SPAs

Here are some common solutions to fix error 404 on SPAs:

1. Redirect to a Custom 404 Page

Configuring the server to redirect broken URLs to a stand-alone 404 error page ensures that users receive a consistent and user-friendly error message. This approach centralizes the handling of 404 errors, providing an opportunity to guide users back to relevant content or the homepage. Here’s an example of Github’s custom 404 error page:

404 Page Example

2. Proper Configuration of Routes

As we saw earlier, one common cause of 404 errors in SPAs is misconfigured routes. Developers must ensure that the application’s routing system accurately reflects the application’s structure. This includes defining routes for each section or page and handling variations such as nested routes.

SPAs often utilize dynamic route parameters to load specific content based on user input or selections. You must ensure the corresponding content is available to prevent 404 errors when users access pages with dynamic URLs.

Additionally, to fix error 404, you can redirect the page to another by implementing a 301 redirect. This informs search engines that the page has been relocated, preventing the display of a 404 error for an existing page. 

3. Implementing Error Boundary Components

Incorporating error boundary components in the SPA can help catch JavaScript errors, preventing the application from crashing and displaying a generic 404 error. Certain client-side navigation libraries, such as React Router or Vue Router, offer mechanisms to handle 404-page not-found errors gracefully. 

In React, you can define a route for 404 errors as follows:

<Route path=”*” component={NotFound} />

4. Server-Side Rendering (SSR)

Server-side rendering involves rendering pages directly on the server before sending them to the client, as opposed to relying solely on client-side rendering (CSR). SSR can enhance SEO by providing search engines with prerendered content, which also helps fix error 404 issues.

For single-page applications facing persistent 404 errors, integrating SSR can be a smart solution. By prerendering pages on the server, SSR ensures that search engine crawlers and users receive HTML content, reducing the likelihood of countering 404 errors due to client-side rendering issues.

However, SSR can be challenging to implement, especially for developers accustomed to client-side rendering. It also requires additional server resources, which can be very costly. Furthermore, SSR may not be a viable solution for SPAs that rely heavily on client-side rendering for dynamic content.

5. Dynamic Rendering 

The best solution to fix 404 errors while also boosting SEO is using a dynamic rendering tool

Prerender, for example, works by intercepting requests from search engine crawlers and serving them static HTML snapshots from a cache. This ensures that search engines receive the same content as users, eliminating the risk of 404 errors due to client-side rendering issues.

Not only that, Prerender also helps improve SEO performance. Since it provides search engines with crawlable content, it accelerates the indexing time and indirectly improves PageSpeed. Consequently, this will boost your SEO health and rankings, giving more visibility to your website.

Furthermore, as your website changes, your content will differ from what’s in the cache. Prerender addresses this through a feature called recaching. This allows developers to schedule Prerender to fetch pages, create new snapshots from updated content, and store them in the cache. This way, search engines will always receive the most up-to-date version of the pages, preventing issues with outdated information or missed optimizations.

As an enterprise SEO tool, Prerender is scalable, cost-effective, and requires no changes to your existing infrastructure. It gives SPAs a lot of benefits, which you can get by getting started with Prerender now.

Prevent 404 Errors for Better SEO Health

Resolving 404 errors is crucial for a smooth user experience and strong SEO performance. With the unique challenges SPAs face in handling URLs, you need to find the right solution.

While various methods exist, dynamic rendering with Prerender is one of the best solutions. It effectively fixes error 404 and also enhances SEO health by ensuring an accurate indexing process. With Prerender, you’re not just resolving issues—you’re optimizing your website for peak performance!

Make your SPAs deliver a flawless experience for users and search engines alike by adopting Prerender today. Start with a FREE 1000 renders per month!

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