Does Google Crawl JavaScript with Body Content

Historically, search engine crawlers like Googlebot could only read the static HTML source code and could not scan and index material written dynamically using JavaScript. This changed, though, with the rise of JavaScript-rich websites and frameworks like Angular, React, and Vue.JS, as well as single-page apps (SPAs) and progressive web apps (PWAs). To properly display web pages before indexing them, Google has modified and discontinued its previous AJAX crawling technique. Although Google can often crawl and index most JavaScript information, they advise against utilizing a client-side solution since JavaScript is "tough to process, and not all search engine crawlers can process it properly or promptly."

What is Google Crawl?

Google and other search engines scan the Web using software called the Google crawler (also known as a search bot or spider). In other words, it "crawls" the Internet from page to website seeking fresh or updated content that Google doesn't yet have in its databases.

Every search engine has a unique collection of crawlers. Regarding Google, there are more than 15 distinct varieties of crawlers, with Googlebot serving as the primary one. Because Googlebot does crawling and indexing, we'll examine its operation in more detail.

How does the Google Crawler Function?

No search engine, including Google, maintains a central register of URLs that is updated each time a new page is made. This implies that Google must search the Internet for new pages instead of automatically being "alerted" to them. Googlebot continuously saunters over the Internet, looking for new webpages to add to Google's inventory of already-existing webpages.

After finding a new website, Googlebot renders (or "visualizes") it in a browser by loading all of the HTML, third-party code, JavaScript, and CSS. The search engine uses this data, which is kept in its database, to index and rank the page. A page is added to Google Index, an additional extremely large Google database if it has been indexed.

JavaScript and HTML Rendering

The lengthy code may be difficult for Googlebot to process and render. The crawler might be unable to correctly render your website if the code is untidy, in which case it will be seen as empty.

Regarding JavaScript rendering, keep in mind that the language is rapidly growing and that Googlebot may occasionally stop supporting the most recent versions. Make sure your JavaScript is Googlebot-compatible to avoid having your website displayed erroneously. Make sure JavaScript loads quickly. Googlebot won't render and index material produced by a script if it takes more than five seconds to load.

When to Use JavaScript for Crawling?

We still advise employing JavaScript crawling selectively when analyzing a website for the first time to find JavaScript, even though Google typically renders every single page. JavaScript is used for utilizing known client-side dependencies for auditing and during the deployment of huge sites.

Selectively crawling all resources (including JavaScript, CSS, and pictures) must be retrieved to display each web page in a headless browser in the background and build the DOM. JavaScript crawling is slower and more labor-intensive.

While this isn't a problem for smaller websites, it can significantly impact larger websites with hundreds or even millions of pages. There is no need to spend time or resources if your website doesn't heavily rely on JavaScript to change a web page dynamically.

A crawler has to read and evaluate the Document Object Model when dealing with JavaScript and webpages with dynamic content (DOM). A completely displayed version of such a website must also be produced after loading and processing all the code. A browser is the easiest tool we have to view the displayed webpage. Because of this, crawling JavaScript is sometimes described as employing "headless browsers."


There will be more JavaScript in the years to come since it is here to stay. As long as it is discussed with SEOs early in creating your website's architecture, JavaScript can coexist peacefully with SEO and crawlers. A crawler is still just ever a replica of the behavior of an actual search engine bot. In addition to a JavaScript crawler, we strongly advise using log file analysis, Google's URL Inspection Tool, or a mobile-friendly testing tool to learn what Google can crawl, render, and index.

Updated on: 28-Dec-2022


Kickstart Your Career

Get certified by completing the course

Get Started