How Google Reads JavaScript?
Introduction
Google Reads JavaScript -JavaScript is the computer language that is the core technology of HTML, CSS, and WWW. What it does is it helps websites on the users’ side to execute codes. It can improve website interaction, buyers’ shopping experience, and more. And when we talk about how Google reads JavaScript, the Googlebot performs JavaScript when interpreting any page.
Google bot fetches a URL from the crawl queue by making an HTTP request. Now, this is the basic process of crawling any web page. And with JavaScript website will use the app shell where the initial part of HTML does not contain the main content. So Google bot must first execute it before it can see the actual content that JavaScript generates.
But interpreting and indexing should be done at different times. Because this will allow us to index content that can be available without JavaScript as soon as possible, and later, you can add content that requires JavaScript.
Now you may be thinking, why do we do this at a different time? When we index content with JavaScript, it will take longer to get indexed and more time to appear on google search results. So we need to add content that requires JavaScript way later.
What is the Impact of JavaScript on SEO?
Most web developers rely on JavaScript, like, for example, Ember or Vue’s, to create an interactive website. But SEO professionals don’t have the same interest because web page loading time increases when you use JavaScript. As a result, web developers tend to sacrifice performance over functionality. So basically, they are hurting SEO.
It is also hurting UX and Core Web Vitals with a lot of dynamic content like, for example, live chat, slow-loading images, product reviews and more. And we add JavaScript to imagine how bad this can be for your website. It will take a lot of time for websites to interact with people.
Some other factors that are affected by JavaScript are CPU limitations, decreased CWV score and more. Therefore, if you are using JavaScript for your website, then you need constantly work on it for better website performance and indexing of web pages.
How does Google Process JavaScript? Google Reads JavaScript
Three processes will help Google to process JavaScript:
- Crawling
- Rendering
- Indexing
Crawling – Google Reads JavaScript
Google bot fetches a URL from the crawl queue by making an HTTP request. Now, this is the basic process of crawling any web page. It also shows if you allow it to crawl in the robots.txt file. So if the file marks the URL as disallowed, then the Google bot won’t crawl that web page.
And with JavaScript website will use the app shell where the initial part of HTML does not contain the main content. So Google bot must first execute the JavaScript before it can see the actual content that JavaScript generates, so this way, Google can crawl the web page one by one.
Rendering – Google Reads JavaScript
Google first decides what resources to render the page’s main content. However, it can be expensive if you want to generate JavaScript on a large scale. It requires enormous computing power to download and execute JavaScript in bulk. And so, Google bot does not take action on rendering JavaScript until appropriately downloaded.
And the system that handles Google rendering is called WRS (Web Rendering Service. WRS receives the URL, renders them, and sends the generated URL back for the following process. There are two types of rendering.
- Server Side Rendering
- Client Side Rendering
Indexing – Google Reads JavaScript
Indexing is the final step, where rendered URL goes for indexing after JavaScript is executed. Let us put it this way Google cannot index URLs until JavaScript renders them. So yes, it is pretty challenging to crawl a JavaScript-based website.
Another thing that has occurred in recent times is the delay between crawling and rendering has gone down due to improvements in the Google bot. And also, there is no surety that Google will execute the JavaScript code that is waiting in the WRS line may be due to errors, Blockage in the Robots.txt files or timeout.
Thus, we hope you have understood that JavaScript can cause issues in SEO when the primary content relies on it. Well, it is not that JavaScript is an absolute evil for a website, but you need to be careful using it because it is very challenging, especially when it is time to crawl the website on Google.
