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Javascript: What Is Javascript And How Does It Apply To Websites?! Technical SEO [2023]

More and more websites are using JavaScript in their construction, in order to add interactivity to websites and provide dynamic content within pages, and it is a very versatile language. An SEO needs to be aware of a site that uses JavaScript because it can have an impact or cause some anomaly when search engines are crawling the site, because Google, despite being able to read this type of language these days, still has some flaws/misinterpretations. Javascript can be incorporated directly into the HTML of a web page or included as an external script. To find out if a site uses Javascript, all you have to do is identify this tag in the HTML code: <script> .

Some Common Uses Of JavaScript On Websites:

  • Form validation: JavaScript can be used to validate user input into forms, ensuring that data is entered in the correct format before submission.

  • Dynamic content: This can be used to create dynamic content that changes based on user interactions: such as sliding carousel images, content tabs and real-time data updates.

  • Site interface improvements: JavaScript allows you to improve the user experience by creating responsive and interactive interfaces. Common improvements include drop-down menus, tooltips and modal dialog boxes.

  • Client-side data manipulation: JavaScript is used to manipulate client-side data without requiring communication with the server. This can be useful for filtering, sorting and modifying data.

  • AJAX (Asynchronous JavaScript and XML): JavaScript can be used to make asynchronous requests to the server to load or send data without requiring a full page refresh.

  • Cookies and local storage: JavaScript can manage cookies and use local storage to save data on the user’s device, which can be useful for things like user preferences and session management.

  • Event handling: JavaScript allows you to respond to user events such as clicks, mouse movements and keyboard inputs, making the site more interactive.

  • Third-party integrations: You can incorporate third-party libraries and APIs into your site using JavaScript to access services such as social media sharing, maps and payment gateways.

  • Animation: JavaScript can be used to create animations on web pages, allowing you to add visual effects and engage users in a more interactive way.

  • Error handling: can help you handle and manage errors gracefully, preventing them from damaging the user experience.

On the SEO side, they have to pay attention to the <script> tag in the Title, Description, Canonical, among others, as they have to make sure that the file is responding quickly, so that this information is delivered to the crawler (search engines) instantaneously, otherwise they risk being left without this information displayed. Javascript sites are fed with external content, which responds as the site is accessed. It is therefore important that this response time is as short as possible, no more than 5 seconds.

Javascript In WordPress

You can enhance the functionality of your WordPress site using JavaScript. Javascript features and functionality can be incorporated using various methods, including plug-ins, and these can be added to the code in this way: add a script to selected pages using a plugin such as “WPCode” (small pieces of code, like scripts); add the script to a specific page or several pages using “functions.php”; or add a Javascript file to your theme’s header <head>.

In some cases of NodeJS applications or others with complex layouts that depend on javascript, some content may not be displayed. One of the methods used to avoid this is pre-rendering, which identifies the type of access to your site and, when it identifies that it is a user, delivers the file for rendering on the client side (client-side rendering), when it identifies that it is a crawler, with Googlebot, the site will be rendered inside the server (server-side rendering). There are various pre-rendering solutions, depending on the technology/framework you’re using. Those using AngularJS can use For those using React, one of the best is react-snap.

Tools that can help you check the JavaScript on your site are “GTmetrix”. In “Google Search Console”, test like Google, choose the desktop and mobile bot and enter “Search” and “Search and Render”. “Merkle SEO” has a range of very versatile tools for checking/testing the site as if it were on the search engine side.



Data from 2016 indicates that more than 96% of websites use JavaScript as their front-end language, including giants such as YouTube and Google. JavaScript is an extremely versatile language that allows you to build websites from scratch, which is why it is the most popular programming language in the world, according to a report by Stack Overflow in 2020! As the most widely used language on websites all over the world, an SEO professional must be prepared to deal with it and know how to solve problems related to it.

Today, many companies need immediate results, but the truth is that they cannot afford to implement SEO internally while leveraging with the priority of their business focus. If you still can’t handle these steps or don’t have the time to put them in place, Bringlink SEO ensures you get the brand visibility and growth you deserve.

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