All You Need to Know About JavaScript SEO eBuilderz featured image

Any programmer you meet will tell you that JavaScript is the best programming language for developing websites. The language is commonly used all over the world by developers to design effective websites. For more than eight years, JavaScript is still on the throne as the king of programming languages. The language is the most preferred language among developers since it was released. This is according to a survey done by Stack Overflow.

The reason why most developers prefer this language is due to its ease of use when building large-scale web applications. Web pages built using JS can update themselves in diverse ways, making them more engaging. To make it even better, the amount of time used to develop websites with JS is reduced using frameworks like ReactJS, Vue, AngularJS, and NodeJS. That is why JavaScript is used to build 96% of websites in the world.

Although JavaScript is used to run the majority of websites online, there seems to be a love-hate relationship between JS and Google. JavaScript makes any website look engaging and interactive by altering and controlling HTML. The UX is further improved when using JavaScript. It is hard to understand why search engines don’t index most sites developed using JS.

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This post seeks to get to the bottom of why Google finds it hard to index JavaScript websites and what you can do to improve things.

What is the effect of JavaScript on SEO?

JavaScript offers a rich interface by allowing the pages of a website to load faster. This also makes it easier to implement the pages. What spoils for it is that depending on how the user interacts with the website, browser fluidity is affected. When this happens, it makes it hard for search engines to grasp the value of the content. When it comes to rendering pages of a website that carry JavaScript content, search engines have limits.

An initial crawl is done by Google, and whatever it finds, it will index it. When it comes to rendering JS, the bots will then go back if there are resources left for that. When this happens, it harms the site’s SEO since content and links that use JS may not be seen by search engines. The fact that JS commands most of the websites in the online world prompts Google to dedicate most of its resources for JS site optimization.

Source:- Google Webmasters

Google wants SEO experts to write their JS-based web pages in a format to make it easy to understand. JavaScript and SEO need to work together to improve website ranks since little is known on how search engines process JS content.

What do search engines look for when processing JavaScript?

The way Google bots process JS pages is not the same as how they process pages that are not written in JS. JS web pages go through three phases of processing. These phases include crawling, indexing, and rendering. Let’s break down these phases for you.

javascript seo -processing Javascript

  • Crawling

This phase involves how easy it is for your content to get discovered. The process is a bit complex and has several other processes. They include crawl queuing and scheduling, seed sets, URL importance, and more. The process starts when Google queues the pages for crawling and then rendering. Fetching pages are done by Google bots through the parsing module. The bots then follow the links on the pages and render them for indexing. Besides rendering, the module also analyses the source code to remove the URLs in the <a href=”…”> snippets.

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To see whether crawling is allowed or not, the bots check the robots.txt file. The bots will pass if the URL is marked disallowed. To avoid this error, it is good to always check the robots.txt file.

  • Rendering

Rendering refers to showing features of the site, such as content and templates. We have two types of rendering: server-side rendering and client-side rendering. Let’s break down what these two types of rendering are.

  • Server-side rendering (SSR)

The pages in this type of rendering are populated on the server-side that’s why it’s called server-side rendering. The page is rendered when a visitor visits the site before it’s sent to the browser. This means that as a bot or a user visits the site, they will get the content as HTML markup. Since Google does not have to render JS elsewhere to access the page, this is helpful to your SEO. Bring a traditional method; SSR is cheap on bandwidth.

  • Client-side rendering

This type of rendering is fairly new in the industry. Client-side rendering lets developers build websites with JS, and they are completely rendered in the browser. This means that this kind of rendering allows each route to be created in the browser directly rather than on a separate HTML page per route. Initially, the rendering will take time since it is going to make several rounds to the server. However, the experience is going to be fast once the requests end through the JS framework.

Once the pages are all crawled, the bots add the pages that need to be rendered to the render queue. But the bots won’t do this if the robots meta tag in the raw HTML code is not supposed to index the page.

Also, you can read Complete Guide: How to Become A Python Developer?

  • Robots meta

javascript seo - Robots meta

The pages to be rendered stay in the render queue for a few seconds depending on the given resources. If resources allow, the pages will be rendered, parsed, and compiled by the Google Web Rendering Service (WRS). It will also execute JavaScript on these pages. The bot will once more parse the rendered HTML for links. It will also queue any URLs for crawling. To index the page, the rendered HTML is used.

  • Indexing

The Caffeine indexer on Google will index the content when WRS fetches the data from databases and external APIs. The indexing phase is all about analyzing the URL, grasping the page for relevance, and keeping the pages that were found and indexed.

Analyzing JavaScript for SEO

If you fail to implement JavaScript properly, it will ruin your SEO. If you want to improve your ranking when using JS, you have to follow these best practices for JavaScript.

Remain consistent with on-page SEO efforts

When you are using JS on your website, It doesn’t mean that you have to ignore all the on-page SEO rules that you know. All on-page SEO rules should be observed just like when you are optimizing your page to attain better ranks. You have to optimize your meta descriptions, alt tags, title tags, and robot tags. To attract your users and make them click on your website, you need to use catchy and unique meta descriptions and title tags. Focus on placing keywords on strategic areas and also know user intent when searching online.

Having an SEO friendly URL structure is a good idea. Using a pushState change in the URL confuses Google when looking for the canonical one. Check for such issues in your URL.

Show your JavaScript in the DOM tree

What makes JavaScript rendering work is when you load the DOM sufficiently. The purpose of the Document Object Model is to show the relationship each element has with one another. It also shows the page structure. You will get this on the page code in the “Inspect element” on your browser. What forms the foundation of dynamically-generated pages is DOM.

There is a big chance that your content is parsed by Google if it appears in the DOM. To know if Google bots are processing your pages, you need to check the DOM.

If the meta robots tag has noindex, Google bots will skip rendering and executing JS. Don’t expect Googlebot to fire events at a page. Only after the page is loaded, is when the content will be added to the page using JavaScript. The page is not going to be indexed if the content is added to the HTML when clicking the button, scrolling the page, and so on.

The last thing when using structured data is that you have to use JS to create the needed JSON-LD. This is then injected into the page.

Don’t block search engines from crawling JavaScript content

Many cony web owners will use a process called cloaking to prevent Google from accessing JS content. Cloaking is when users can see the content but not search engines. This process violates Google’s Webmaster Guidelines, and you risk being penalized if you are caught using it. Just work on the issues that prevent Google from ranking JS pages and don’t hide its content from search engines.

There are cases when the site host is blocked by mistake. This will prevent Google from accessing the JS content. These are sites that have other child domains, each with a different use. Since these subdomains are treated as separate websites, each should have its separate robots.txt. If you own such sites, check whether search engines are blocked from accessing rendering resources.

Use relevant HTTP status codes

When crawling a page, crawlers use HTTP status codes to find issues. This means that you need to use a relevant status code to tell the bots that the page needs to be crawled and indexed. To tell the bots that the page was moved to another URL, you need to use a 301 HTTP status. This way, Google will update its index accordingly.

javascript seo - Use relevant HTTP status codes
Serge Bezborodov X G2 JavaScript SEO


Check for duplicate content and fix it

Most of the time, you may get different URLs for the same content when using JavaScript. When this occurs, you will find that the website has duplicate content due to parameters with Ids, capitalization, or Ids. Check to find if there are any such pages and select your preferred URL. To avoid confusion from search engines, set canonical tags.

Get rid of lazy-loaded images and content

For your SEO to work, you need to have fast loading websites. To maintain UX Best practices, you need to look for lazy loading images and content and fix them. This will reduce the initial loading speed. You may have a fast loading page, but it’s not visible to search engines. This prevents crawlers from executing JavaScript, which will hurt your SEO efforts.

Images contribute to extra organic traffic. If you have lazy loading images on your website, search engines will fail to pick them. Your users may love lazy loads; however, do it with care to avoid bots from leaving important content.

Use JS SEO tools

The good news is that we have plenty of JavaScript SEO tools in the market. These tools can help you find and fix JavaScript code related issues. Here are some of them:

URL inspection feature – You can get this feature in Google Search Console, and it’s used to tell whether Google’s crawlers can index your pages or not.

Search engine crawlers – With these tools, you can monitor and test how search bots crawl your web pages.

Page Speed Insights – This is one of Google’s SEO tools that allows you to share details of your website’s performance. It also gives solutions on how to improve it.

Site Command – If you want to see whether Google has indexed your content properly, this is the right tool for you. You just need to enter the site: [website URL] “text snippet or query” as a site command on Google.

The challenges of JavaScript SEO

At this point, we believe that you have an idea or two of JavaScript and how search engine engines process its content. We have also given you SEO tips to make your efforts successful when using JS. All that is not enough because there are also other JavaScript challenges that you need to overcome. Many of these challenges come from optimizing JS-based websites. Let’s take a look at a few of them:

1.    JavaScript and CSS files that are not minified

When auditing your SEO using SEO tools, you will come across unminified JavaScript and CSS warnings. After some time, white spaces, unnecessary codes, hosting on external servers, and comments in source code weigh down CSS files and JS. This will slow down your website. To enhance your SEO, ensure that you get rid of these issues.

2.    Use of hash in the URLs

John Mueller said once at an SEO event that when we see any kind of hash, we conclude that the rest is irrelevant. However, most JS sites use a hash to generate URLs, which is not good for SEO.

Source:- AngularConnect

URLs need to be Google friendly if you want to make your SEO efforts in JS successful.

3.    Ignoring the internal link structure

To find URLs on your site, Google needs proper <a href> links. Google bots won’t see these links after clicks on a button when added to the DOM. SEO will suffer because most web owners fail to check these issues. Make the traditional ‘href’ link available for bots. One tool that will help you check your links is called when auditing is called SEOprofiler. This tool will help you with your site’s internal link structure by improving it.


Even though search engines and JavaScript are not always at par, the programming language helps to enhance website functionality. Site ranking is affected because JS affects how search engines crawl and index websites. To make things better when using JS-based sites, SEO experts need to know how search engines process content on JS sites. This will allow them to take measures by marrying JavaScript to their SEO strategy.

You need to look into this issue when you find it hard to get your content on Google if you are running a JS website. The tips and info that we have mentioned above will help you boost your returns by optimizing JavaScript for SEO.


Here are a few more topics that you shouldn’t miss:
How to perform and SEO site audit in 1 hour
What are backlinks and why are they beneficial to SEO?
Complete Guide: How to Become A Python Developer?

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