Single-Page Applications (SPAs) in SEO

The Internet and the way people use it are constantly changing. This is where SEO specialists must constantly respond by creating interactive experiences online. This can be done, for example, by using Single-Page Applications (SPAs).

SPAs allow the user to see the content of a website in a dynamic way, but in fact the website consists of only one page. This way, the loading time reduces and the user can scroll faster.

Using SPA offers many benefits, but also raises questions regarding SEO. The optimal use of SPAs must seek a balance between creative understanding of the user experience and technical expertise. In this article, I explore these issues and explain how using SPAs can provide better search results to rank higher in Google.

The meaning of SPA

SPA – also known as Single-Page Application – is a major innovation in the online world that offers a different way of browsing. Instead of traditional websites divided into headings with new pages underneath, SPA displays all content on one page. So new pages do not have to be reloaded all the time. Only the first page load is necessary.

However, an SPA does still load the necessary data, often via AJAX requests. JavaScript is used to integrate new information into the existing web page. This means that the content changes without a change in the URL. This speeds up the user experience.

On an SPA, the user interface is updated in real time . This is done the same way desktop applications update a page. Because the URL does not change, there is continuous interaction for the user. Modern JavaScript frameworks such as React, Angular or Vue manage these dynamic updates and are responsible for the operation of the application.

Besides the benefits of SPA, it also brings some challenges, especially in the SEO sector. SEO specialists must find other ways to ensure that search engines still crawl and index the content. Technical knowledge and skills are combined with strategic planning to make the SPA more visible and findable. However, these challenges are not very common. Especially in the case of interfaces that are not indexed, problems arise more easily.

Examples SPAs

Many modern apps and websites are SPAs. In the process, interfaces are often customized to users’ personal preferences. These are some examples of well-known SPAs:

  1. Gmail. In Gmail, all messages come in on 1 page. All the different tasks you can perform fall under the same URL.
  2. Facebook. It is possible to scroll endlessly through a Facebook feed and perform various actions without reloading the app or website.
  3. Google Maps. Retrieving routes and viewing the map from Google Maps can also be done without reloading the page each time.
  4. Netflix. Netflix allows you to quickly scroll through its full selection to choose a movie or series.
  5. X (formerly Twitter). X is officially a PWA, but the main website contains SPA features. Content is loaded dynamically here.
  6. Instagram. On Instagram, content is displayed dynamically. Much of Instagram, then, is a SPA.
  7. Airbnb. On one page, you can scroll through all the accommodations without changing URLs.
  8. GitHub. GitHub’s web interface has SPA elements, particularly the project management and code exploration sections.

The above websites use SPA with the goal of providing users with a fast and dynamic experience. This is especially useful for complex Web sites with a lot of user interaction.

Technical challenges

SPAs use JavaScript, which helps load content without requiring a full page refresh. This sometimes involves technical challenges. To minimize the challenges, search engines like Google have invested in a better ability to handle JavaScript. This has reduced, but not completely resolved, the limitations.

User execution of actions is one such challenge. With such an action, new content is loaded. In some cases, search engines cannot detect these dynamic updates and a discrepancy occurs between the user’s view and the search engine’s indexing.

In addition, SPAs often rely on client site rendering where JavaScript frameworks run on the browser to build the page (see my articles on dynamic rendering and server side/client side rendering). This only increases the discrepancy.

Client rendering provides a smooth and interactive user experience, but initially, when crawling a site, the bot receives only the bare HTML template, with the content not yet populated. The bot may be indexing an empty page, which will bring down search engine results.

Managing the crawl budget is also a challenge. Search engines have limited resources used for crawling a website. SPAs are often complex and dependent on JavaScript, which quickly consumes the budget.

The benefits of SPA for SEO

In addition to the aforementioned challenges of SPA for SEO, there are also benefits to improving an SEO roadmap.

Previously, HTML was the basis of Web content, CSS was responsible for formatting, and JavaScript was used for interactive features. Today, JavaScript is present on more than 98% of all websites and is capable of adapting a page’s content to user actions.

SPAs, however, eliminate the need for HTML, CSS or JavaScript for every action. Instead of requesting different sources with each action, when the website is opened, all sources are requested at once, allowing the browser to then do its job.

This new way of working ensures that the websites are a lot faster. This greatly improves the user experience. Research has shown that visitors want to wait a maximum of three seconds for a page to load and leave the page if the load time is higher. With an SPA, load times are generally shorter, but if implemented incorrectly, the opposite can happen, negatively impacting SEO.

SPAs in the basics

Angular, React and Vue are well-known leading frameworks for building SPAs. The difference between the tools is mainly in supporting libraries and APIs, but they have in common that their client-side rendering is of good quality.

JavaScript reduces the number of requests to the server browser. The speed of the user experience goes up, but the use of JavaScript negatively affects search engine results. Search engines experience the Web site in a different way than users and mostly see inaccessible content. Search engines think the page is still empty, while users see dynamic content, which is constantly being reloaded.

Above all, it is the users who benefit most from SPAs. Not only because of speed, but also because SPAs with weak connections are still easily accessible. This is because SPAs cache all required resources locally immediately after the initial request. Moreover, the layout does not shift.

Although additional efforts are needed to improve SEO, SPAs offer enough benefits to be applied permanently. Moreover, a good user experience contributes to better SEO.

Challenges of SPAs on SEO

As mentioned earlier, using JavaScript with dynamically loaded content can cause search engine problems because search engines only see an empty page. This is because traditional search engines are built to index and crawl static HTML content, and SPAs consist of empty HTML. Only after the JavaScript is executed is the HTML filled with content. Search engines thus face incomplete information.

Moreover, SEO uses different URLs for each content page. Since Spas use only one HTML page and therefore the URL does not change, an SPA must be modified to be relevant to search engines. It is important that SPAs are provided with relevant SEO metadata for each individual section within the application.

Also, the fact that SPAs are more complex does not help the SEO. The crawl budget will go through it faster, which can lead to parts of the website being overlooked within the time search engines allocate to crawling a website.

SEO optimization requires proper architecture of SPAs using server-side rendering (SSR). SSR generates the content server-side before sending it to the client. You can see a full page by implementing pre-rendering techniques.

To ensure that search engines treat each section of the SPA as a unique element, dynamic meta tags and structured data must be properly deployed.

The following is a summary of the biggest challenges:

ChallengeDescription
Indexing of contentSPAs load content dynamically with JavaScript, which can make the content invisible to search engines that index only HTML.
Crawling efficiencyHeavy JavaScript can exceed the crawl budget, preventing search engines from indexing the full content of the SPA.
Use of meta tagsDynamically loaded pages within an SPA often lack unique meta tags per section. These are essential for good page indexing.
URL managementSPAs often use only one URL. This causes SEO problems because each content requires a unique URL.
Structure of URLs.The fact that SPAs do not possess a traditional link structure makes the links less findable and reduces their value.
Server-side rendering (SSR)SSR is necessary to preload SPAs for search engines. Implementing them can be complex.
Pre-renderingPre-rendering generates static snapshots for crawlers. This requires additional setup and maintenance.
User engagementAlthough SPAs improve interaction, measurement issues can arise because traditional analytics are not optimized for SPAs.
Structured DataDynamically injecting structured data into SPAs presents more technical challenges than in traditional Web sites.
Challenges for SPAs regarding SEO.

Tips for SEO when using SPAs

To apply SEO so efficiently to SPAs, the tips below are helpful. Here I would immediately point out that if your organization runs an SPA, it is important to work with a specialist to create a customized strategy.

  1. Use a specialist: The complexity of SEO related to SPAs requires a specialist who can create a good customized strategy.
  2. Use universal JavaScript: Use universal or isomorphic JavaScript to generate the server-side of the page, so the search engines do not have to execute and render all the JavaScript files.
  3. Pre-load HTML pages: Pre-load all HTML pages and store them in the server cache. This allows these to be presented to search crawlers and prevents search engines from encountering empty pages. Use services such as BromBone or Prerender for this purpose.
  4. Implement feature detection: Implement feature detection for improving the experience with different code sources. In this way, the base page becomes accessible to both crawlers and users.
  5. Use different URLs: Although SPAs only require the use of one URL, it is better for SEO to use different URLs. This can be done using the History API.
  6. Organizing error codes: In the case of error codes (including 404 and 500), it is smart to create separate views and modify the JavaScript files so that browsers are directed to the correct view.
  7. Appropriate titles and meta-descriptions: For optimal SEO, appropriate and unique titles and meta-descriptions are indispensable for each individual section.
  8. Robots meta tags : Through robots meta tags, provide instructions to search engines on how to crawl and index pages to ensure that this is done correctly and avoids duplication and incorrect indexing.

Summary

Although SPAs seem to pose many challenges to SEO at first, by using proper techniques and strategies you can optimize SEO as much as possible. For example, use isomorphic JavaScript, feature detection, pre-rendering and History API.

Moreover, manage meta tags dynamically and implement robots meta tags appropriately. This makes SPA content accessible and indexable by search engines. By employing the right strategies, SPAs are good resources in a rapidly changing and competitive world, where user experience is a big factor in SEO.

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Senior SEO-specialist

Ralf van Veen

Senior SEO-specialist
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I have been working for 10 years as an independent SEO specialist for companies (in the Netherlands and abroad) that want to rank higher in Google in a sustainable manner. During this period I have consulted A-brands, set up large-scale international SEO campaigns and coached global development teams in the field of search engine optimization.

With this broad experience within SEO, I have developed the SEO course and helped hundreds of companies with improved findability in Google in a sustainable and transparent way. For this you can consult my portfolio, references and collaborations.

This article was originally published on 27 March 2024. The last update of this article was on 27 March 2024. The content of this page was written and approved by Ralf van Veen. Learn more about the creation of my articles in my editorial guidelines.