Javascript SEO Overview

Javascript is one of the most popular programming languages in the world. It’s used to create dynamic and interactive websites that power the most popular websites that we’ve come to love. Frameworks like ReactJS and Angular have revolutionized how Javascript is used to create websites, but what many people don’t know is that Javascript can have a significant impact on your ability to rank within search engines if you’re not careful.

Javascript SEO History

In the past, search engines had difficulty indexing and ranking Javascript-heavy websites. This is because their algorithms were not designed to handle executing the dynamic content that Javascript creates. As a result, many SEOs advised against using Javascript frameworks for fear that it would hurt their website’s ranking.

However, things have changed in recent years. The major search engines have made significant strides in their ability to index and rank Javascript-based websites. In fact, Google has published official documentation regarding the potential SEO impacts of using a Javascript-heavy website. – This doesn’t mean we’re completely in the clear just yet though.

It’s important to keep in mind that while search engines have come a massively long way, there are still some potential issues that can arise from using Javascript frameworks. Some issues include lazy loading content and client-side rendering. In this article, we’ll take a look at what Javascript SEO is and some of the potential issues that you should be aware of if you’re using React.JS or another Javascript framework.

What is Javascript SEO?

Javascript SEO is defined as optimizing a website for ranking within search engine results pages (SERPs) when Javascript is used to generate dynamic content. This can be a challenge because Javascript is not always easy for search engine bots to crawl, render, index and rank.

In order to understand how Javascript SEO works, first, it’s important to know how search engines crawl Javascript-heavy websites.

Google Processes and Renders Javascript Web Pages in 3 Core Ways:

  1. Crawling
  2. Rendering
  3. Indexing

Googlebot queues pages for both crawling and rendering. It is not immediately obvious when a page is waiting for crawling and when it is waiting for rendering.

Googlebot begins by fetching the URL from the crawl queue by making an HTTP request. The first thing it does is check if the page allows crawling by reading the site’s robots.txt file. If the page doesn’t allow indexing, Googlebot stops the HTTP request immediately and skips the URL entirely.

Next, Googlebot scans the HTML source code of the page and scans for links using the “href” attribute. It proceeds to add these discovered URLs to the crawl queue. To prevent link discovery, add the “nofollow” attribute to your links.

Make sure you’re following Google’s guidance when it comes to the proper way to handle links and ahref attributes when using Javascript to inject these into the DOM.

If a website is using Javascript to generate dynamic content, that content may not be indexed by the search engine unless the proper steps are taken. This can hurt your ranking because the search engine won’t be able to see all of your website’s content which could impact your relevancy score.

Issues With Javascript Frameworks and SEO

Lazy Loading

Lazy loading is a technique used to improve website performance. It delays the loading of images or other content until it’s needed. This can save time and data for users with slower internet connections.

The issue with lazy loading is that it can cause problems for search engines. This is because the content is not loaded until after the initial page load or until the user interacts with the page. As a result, search engine crawlers may not be able to index all of the content on the page.

Solution

To get around this, you can use a technique called “pre-loading.” Pre-loading allows you to load content before it’s needed. This ensures that the content is available for search engines to crawl and index.

To pre-load content, you can use the “prerender” attribute. The prerender attribute tells the browser to load the specified content before it’s needed. You can add the prerender attribute to any element on your page, including images, scripts, and links.

For example, let’s say you have an image on your page that’s lazy-loaded. To preload the image, you would add the following code to the element: <img src=”image.jpg” alt=”Image” prerender>

This tells the browser to load the image before it’s needed. As a result, the search engine crawler will be able to index the content on the page. Limitations of PreloadingPreloading is a great solution for lazy-loaded content. However, there are some limitations to using this technique. First, preloading only works if the browser supports it. Currently, only Google Chrome and Safari support preloading. Other browsers, such as Firefox and Edge, do not support preloading.

Second, preloading only works if the content is in the initial HTML. If the content is generated by a script after the page loads, preloading will not work.

Third, preloading only works for visible content. If the content is not visible when the page loads, preloading will not work.

Finally, preloading can impact website performance. This is because the browser will load the content even if it’s not needed. As a result, you should only use preloading if you’re sure that the content is needed.

 

Infinite scroll: Infinite scroll is a technique used to load content continuously as the user scrolls down the page. This can provide a better user experience, but it can also cause problems for search engines. This is because the content is not loaded until the user interacts with the page. As a result, search engine crawlers may not be able to index all of the content on the page.

Solution

To get around this, you can use a technique called “pagination.” Pagination allows you to divide content into separate pages. This ensures that the content is available for search engines to crawl and index.

To implement pagination, you can use the “rel” attribute. The rel attribute tells the browser how to load the specified content. You can add the rel attribute to any element on your page, including images, scripts, and links.

For example, let’s say you have a script that loads content continuously as the user scrolls down the page. To paginate the content, you would add the following code to the element: <script src=”content.js” rel=”next”>

This tells the browser to load the content on the next page. As a result, the search engine crawler will be able to index the content on the page.

Ajax: Ajax is a technique used to load content dynamically without refreshing the page. This can improve website performance, but it can also cause problems for search engines. This is because the content is not loaded until after the initial page load or until the user interacts with the page. As a result, search engine crawlers may not be able to index all of the content on the page.

To get around these issues, you can use a technique called “progressive enhancement.” Progressive enhancement is a technique used to load content progressively. This means that the content is loaded in stages. The first stage loads the basic content, and the subsequent stages load additional content.

For example, let’s say you have a page with infinite scroll. To implement progressive enhancement, you would first load the basic content of the page. Then, you would load additional content as the user scrolls down the page. This ensures that the search engine crawler will be able to index the content on the page.

ReactJS

React is a popular Javascript framework created by Facebook. It’s used to create user interfaces and web applications. React is unique in that it uses a virtual DOM (Document Object Model). This means that React only updates parts of the DOM that have changed, which can improve performance.

The issue with React is that it can cause problems for search engines because of the way that it renders content. React uses client-side rendering, which means that the content is not rendered on the server. Instead, it’s rendered in the browser. This can cause problems for search engines because they may not be able to index or view all of the content on the page.

Solution

There are a few ways to get around this issue. First, you can use server-side rendering. Server-side rendering means the content is rendered on the server before it gets sent to the browser. This ensures that all of the content is available for search engines to crawl and index.

Another solution is to use a library like React Snapshot. React Snapshot takes screenshots of your React application and saves them as static HTML files. These static HTML files can be crawled and indexed by search engines.

ReactJS FrameworkAngular

Angular is a popular Javascript framework created by Google. It’s used to create single-page web applications. AngularJS is unique in that it uses two-way data binding. This means that changes to the model are automatically reflected in the view (and vice versa).

The issue with Angular is that it can cause problems for search engines because of the way that it renders content. Like React, AngularJS uses client-side rendering. This means that the content is not rendered on the server. Instead, it’s rendered in the browser. This can cause problems for search engines because they may not be able to index or view all of the content on the page.

Solution

There are a few ways to get around this issue. First, you can use server-side rendering. Server-side rendering means the content is rendered on the server before it gets sent to the browser. This ensures that all of the content is available for search engines to crawl and index.

Another solution is to use a library like AngularJS Universal. AngularJS Universal renders Angular applications on the server. This means that all of the content is available for search engines to crawl and index.

Conclusion

Javascript SEO is a complex topic. There are a lot of different factors that can impact your website’s ranking in the search results. However, by understanding the issues and potential solutions, you can ensure that your website is well-optimized for search engines.

Helpful Tips:

You can use the Google search console to check if Google can render your Javascript pages.