The impact of Javascript on SEO in 2024

It is important to understand how search engines deal with modern technologies such as JavaScript. Marketing managers and CMOs in particular use it to ensure that their Web sites perform optimally in search results.

In this article, I discuss how search engines process JavaScript and the importance of an accessible website structure.

Understanding how search engines process JavaScript

Understanding how search engines crawl and index JavaScript is very important. The impact on the visibility of content with JavaScript in search results is very high. Accordingly, Google has significantly improved its approach regarding this topic in recent years.

Google today can crawl and render JavaScript content. Thus, the search engine sees the content in the same way as the user. However, this process is more complex than crawling static HTML. In the case of improper application, this process can lead to visibility problems. Google has a detailed explanation of how to access the search engine.

How does Googlebot discover new pages?

Crawling and indexing by Google is critical to making pages visible in search results. This process is as follows:

1. Crawling:
   • Starting point: Google begins by crawling a list of known URLs from previous crawls and sitemaps submitted by website owners.
   • Googlebots: Googlebots are Google’s “crawlers” or “spiders” that explore the Web. They visit Web pages, discover new or updated pages, or follow links.
2. Indexing:
   • Page processing: After crawling follows processing the page content. Google immediately processes text, images and videos.
   • Creating Index: Google’s index stores the processed information. This is a large database with all the information found.
   • Using keywords: Google identifies keywords to understand what the page is about.
3. Ranking:
   • Using Index: Google uses the index in a search to find relevant results.
   • Ranking: Next, the pages are ranked based on various factors, think relevance and site quality.
4. Continuous process:
   • Updates: Perform regular updates. Crawlers are more likely to visit websites that are regularly updated to find new content.
5. Challenges with JavaScript:
   • Challenges for Googlebots: Sites with lots of JavaScript are more difficult to crawl by Googlebots.
   • Solutions: Google can handle JavaScript better than before. However, it is still important to make essential content and links accessible in the HTML.

Google can provide the most relevant information based on searches. Moreover, SEO optimization is very important for effective indexing. See image below:

Accessible structure

It is very important for the website to have a good and accessible structure. This also helps improve SEO. The base structure should always be kept accessible, even when JavaScript is not loaded or disabled.

Search engines crawl and index the content of an accessible website more effectively. This is important because some search engines and Web crawling tools experience challenges in handling JavaScript. An accessible structure increases the likelihood that the content will be indexed in search results and that the page will rank higher in Google.

Serverside, client-side or dynamic rendering

The choice between server-side and client-side rendering plays an important role in the SEO roadmap. I explain the differences between the two methods and elaborate on the influences on SEO. Please also refer to my extensive article for this.

Server-side rendering

With server-side rendering, the entire page loads on the server before it is sent to the browser. Search engines can thus crawl and index easily, which has a positive effect on SEO.

Each click loads a new page. This type of rendering is very beneficial for SEO and visibility, but the user may experience slower load times. This is especially true for more complex websites.

Client-side rendering

Client-side rendering is rendering of the page in the user’s browser. Usually this is done through JavaScript. Less data is exchanged between the server and the browser. This makes for faster load times.

For example, in single-page applications (SPAs), the content changes dynamically without reloading the page. However, this can create difficulties for SEO. Search engines struggle to index the dynamically loaded.

Dynamic rendering

Dynamic rendering combines server-side and client-side methods. The server chooses server-side or client-side rendering, depending on the user – a person or a search engine. This is especially useful for complex sites where both a good user experience and good SEO are important. However, indexing is more complex and requires more maintenance.

The impact of dynamic content on SEO

JavaScript is often used to create interactive elements on Web pages. It is important that search engines properly index this content. Failure to do so can lead to indexing problems and leave valuable, interactive content visible in search results.

Example: a product catalog that loads dynamically via JavaScript. Products remain invisible in search results if the content is not accessible to search engines through server-side rendering or in the source code.

So make sure dynamic content remains accessible to search engines, for example, by implementing dynamic rendering and by keeping key content and navigation accessible at all times. This can be done even if JavaScript is disabled. In this way, the content is not only user-friendly, but also SEO-friendly.

Influence of JavaScript frameworks

JavaScript frameworks have an important role in the creation and functionality of Web sites. Each framework has a unique impact on SEO. This is important for user experience and SEO.

Below, I discuss further the impact of different JavaScript frameworks on SEO. This is important for web developers and marketers.

Angular

Angular is known for its power. Its client-side rendering creates challenges. Consider search engine crawling problems. Server-side rendering via Angular Universal helps solve these challenges. This makes the content more accessible to search engines.

React

React may face the same challenges as Angular. These tools is suitable for creating dynamic user interfaces. React is primarily client-side focused.

Techniques such as server-side rendering – for example, with Next – make content more SEO-friendly.

Vue.js

Vua.js is flexible. However, like the other tools, it can cause problems in SEO if used improperly.

When using server-side rendering and pre-rendering, you can improve the SEO performance of a Vue.js application.

Ember.js

Ember.js focuses on convention-over-configuration. It has built-in server-side rendering capabilities with FastBoot. This makes a page more SEO-friendly.

Backbone.js

Backbone.js is a minimalist framework. It offers less direct SEO solutions than other frameworks. SEO specialists need to apply manual configuration if they want to improve their SEO.

Which framework is most suitable depends on the ability to implement server-side to dynamic rendering.

Overview of frameworks

Below are the five JavaScript frameworks previously mentioned in one table, along with their SEO challenges and solutions:

This table provides a quick overview of the challenges and solutions related to SEO for each of these popular JavaScript frameworks.

Tools and techniques for JavaScript SEO testing

Use the right tools and techniques to optimize websites with JavaScript in the search engines. The tools below provide insight into how search engines display and index JavaScript content.

Google Search Console

Google Search Console is useful for monitoring page indexing and identifying any crawl errors.

With insights into the website’s search performance, quick action can be taken to improve SEO.

URL inspection in Search Console

The URL inspection feature in Search Console, formerly Fetch as Google, can verify that Google loads and displays JavaScript content correctly. This provides insights into the accessibility of specific pages to Google.

Lighthouse

Google’s Lighthouse helps analyze the performance, accessibility and SEO of Web pages. It provides detailed reports with insight into areas of improvement.

Screaming Frog SEO Spider

Screaming Frog SEO Spider is great for crawling websites to quickly identify SEO challenges. This boosts how search engines crawl a Web site and provides insight into potential content indexing problems.

JSDOM

JSDOM is node.js lets users test Web pages in a simulated JavaScript-rich environment. This ensures that all elements are loaded correctly and accessible to search engines.

The tools at a glance

The table below shows the pros and cons of different tools for testing problems with JavaScript and SEO. The score from 1 to 100 indicates how interesting each tool is for this purpose:

The above scores are based on the effectiveness of each tool in identifying and solving problems with JavaScript and SEO.

Summary

JavaScript can contribute to an effective SEO strategy. The same goes for a clear website structure.

For marketers, it is essential to know well how search engines handle JavaScript. Based on this information, they make more thoughtful decisions and contribute to a website’s visibility and findability. This is essential for success today.