How Search Engines Crawl and Index JavaScript Content: What SEOs Must Know

JavaScript, being one of the core components of the World Wide Web, is responsible for powering most of the websites today. As of 2025, JavaScript is still one of the most popular programming languages among developers, with over 98% of websites utilising the framework. As JavaScript has become an important asset in web development, this has often raised a critical question for both SEO professionals and web developers alike: Does Google index JavaScript?

The short answer is yes, for most of the time. JavaScript web content pages get indexed well by search engines. This makes it essential for web developers to understand JavaScript SEO for heavy websites. This allows you to implement strategies to properly crawl and index them. Let’s learn more about how Google handles JavaScript indexing and some of the best practices to ensure that your JavaScript-powered websites are search engine-friendly.

Timeline of Google Indexing JavaScript

Before the JS indexing process became a widespread norm, search engines, including Google, used to crawl and index websites. However, most of the sites consisted of basic HTML content. Before we dive into the JavaScript indexing process, let’s take a look at how Google has crawled and indexed web content over the years.

• Before 2009: Support for Google index JavaScript was limited as it primarily crawled and indexed HTML content.

• 2009–2015: The AJAX crawling scheme was introduced by Google, and most sites were required to provide HTML snapshots of dynamic content.

• 2015-2018: By leveraging a headless Chrome browser, the earliest form of Google indexing JavaScript and rendering was made possible.

• 2018–present: Modern JavaScript crawling and indexing made possible with an up-to-date Chrome version, coupled with the support for the latest web technologies, namely universal rendering, stateless rendering, asset caching, and cloaking. For a better understanding of how this process works, referring to a comprehensive JS rendering guide can be extremely helpful.

How Google handles JavaScript indexing

Does Google index JavaScript? You got the answer to that in the intro itself. 

But how Google handles JavaScript indexing process? That involves three steps, which are explained as follows:

• Crawling
• Rendering
• Indexing

Source:

Crawling

The initial phase of Google index JavaScript starts with Googlebot making an HTTP request and picking up a URL from the crawl queue. It then checks if the site is allowed for crawling in the robots.txt file. If it is disallowed, the URL is skipped; however, if it is allowed, Googlebot downloads the HTML and scans it for any <a href> links. 

If any such links are found, they are added back to the queue for future crawling. When it comes to JavaScript-heavy websites utilising the app shell model, the content isn’t present in the initial HTML. Googlebot has to execute the JavaScript before being able to see the actual page content.

Rendering

The rendering phase is the most important phase of the JS indexing process. Here, Googlebot processes the crawled URLs to understand the JavaScript content. Unless there is a “robots meta tag” or an X-Robots-Tag HTTP header that explicitly tells not to index the page, Googlebot queues all the crawled pages for rendering. 

Depending on Google’s resources and the complexity of the page, the page may stay on this queue for a few seconds. If you didn’t know, it is quite expensive to render JavaScript. This is because it requires significant computing power to download, analyse, and execute.

Therefore, once the resources are available, a headless version of Chromium is used by Googlebot to render the page, where the JavaScript is executed. The rendered HTML page is parsed by the Googlebot for links, and if anything URLs are found, they are added to the crawl queue for future exploration. 

You have to keep in mind that not all bots can execute JavaScript. Due to this, using server-side rendering or pre-rendering techniques is a wise choice as it makes the site faster for users and crawlers.

Indexing

Once the HTML is rendered and the JavaScript is executed, Google proceeds to index the page. It begins by analysing the page and extracting essential contents such as text, images, structured data, metadata, and internal/external links. After extraction, the Google index JavaScript-generated content is stored in Google’s index, which is then used as search results. If there is any content missing due to improper execution of the JavaScript, it may be excluded from indexing.

Debunking The JavaScript SEO Myths

When it comes to Googlebot and JavaScript, there are various myths circulating on the web. Some of them have been analyzed and debunked by a joint study conducted by Vercel and MERJ Research. According to their study, they analysed over 100,000 Googlebot fetches across various websites, with data being collected from sites such as nextjs.org, monogram.io, and basement.io, etc, to test Google’s SEO capabilities.

One of the myths was that Google can’t render JavaScript content, however, it was debunked with valid proof. By fetching 100,000 fetches, 100% of HTML pages were effectively rendered without issues, including sites with complex JavaScript interactions. Also, the React-based framework, Next.js, was fully rendered by Googlebot, thereby confirming its compatibility with modern JavaScript frameworks.

You can check out the link above to learn more about the various Googlebot and JavaScript myths.

How to check if Google is indexing JavaScript content correctly

From the above sections, you have understood how Google handles JavaScript indexing. But how do you know that the JS indexing process is done correctly by Google? 

We have listed some of the methods to find out whether Google’s indexing JavaScript is correct or not.

Perform a site: search

Through this technique, you can find out whether your website has been indexed. Apart from telling how many pages of your site are indexed, it also tells whether your Google index JavaScript-generated content is being indexed properly. Conducting a site: search is easy. Just go to Google and type in “site:yourdomain.com” (replace “yourdomain.com” with your actual domain name). Once done, the search engine will then return a list of all the pages it has indexed.

If your site contains other pages with JavaScript-generated content and you want to know if it loads correctly, just do a site: search for the specific page, as shown in the image below:

Even though a site: search helps find whether the Google index JavaScript process is correctly done, this is not a comprehensive audit process, and it is recommended to try other indexation methods.

Use Google Search Console

Want another way to know how to check if Google is indexing JavaScript content correctly?

Using the URL Inspection Tool in Google Search Console. You can do that by:

• Load the GSC dashboard
• Select your property.
• Enter the URL to inspect and hit “Enter”.

If the URL has been indexed, you’ll see a message saying “URL is on Google” with a green checkmark.

By clicking on “Test Live URL”, you can see a live rendering of your indexed webpage. If you can’t find any content, then Google has not indexed it. Once done, click the “View Tested Page” to see the rendered page. It is essential to look at whether the JavaScript-generated content is in the rendered HTML. This is because the screenshot may not include the entire page.

You can also utilise third-party tools such as Screaming Frog, Ahrefs, Semrush, etc, to check whether Google has indexed your JavaScript content properly.

Winding Up

Does Google index JavaScript? The answer and how search engines crawl JavaScript must be clear by now. Understanding JavaScript and the vital role it plays in the development of dynamic websites is crucial for search engine optimization agency, experts or professionals, and developers. When it comes to Google indexing JavaScript content, it has significantly improved since 2015. As web technologies are being improved, it is essential to build up your technical SEO knowledge, coupled with adhering to the best practices shared by Google to avoid problems in your site’s crawling and indexing.