JavaScript SEO: Everything you need to know in 10 points

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In the world of SEO, JavaScript SEO is an increasingly common term.

But what exactly does this mean? In this article, we're going to explore the 10 key points for understanding and optimising the use of JavaScript as part of the natural referencing of your website or web applications.

1. What is JavaScript?

Before talking about JavaScript SEO, it is essential to understand what JavaScript itself is.

JavaScript is a programming language used to add interactive and dynamic functionalities to websites and web applications.

Its main function is to automatically modify the content, structure and style of a page in real time, thereby improving the user experience.user experience.

2. How does JavaScript influence SEO?

JavaScript affects SEO because search engines such as Google need to correctly analyse and interpret the scripts on a web page in order to index its content and determine its ranking in search results. If content generated by JavaScript is not correctly rendered and accessible to exploration robots (crawlers), it can lead to indexing and visibility problems for your website or web application.

3. Client-side vs. server-side rendering

There are two main rendering methods for displaying content on a website :

Client-side rendering (or "client-side rendering", CSR): Content is generated and displayed in the user's browser using JavaScript executed by their device. This can cause SEO problems because crawlers will only see the initial source code of the page, without seeing the dynamically generated content.
Server-side rendering (or Server-side rendering, SSR): Content is generated and displayed directly on the server hosting your website, before being sent to the user's browser. In this case, search engines see the full content, including that generated by JavaScript, as it is already integrated into the code. HTML The page is "finished" when you explore it.

4. Progressive improvement and graceful failure

Using thegradual improvement means creating a website or web application whose basic functionality is accessible even when JavaScript is not available or taken into account by the browser. So instead of forcing users to have JavaScript to view content, it offers a simplified functional experience and is progressively enriched by JavaScript.

Graceful failure, on the other hand, involves designing websites or applications in such a way that they continue to offer basic functionality even when certain parts of the JavaScript code fail or are not supported. Both approaches ensure that content is accessible to search engines and users, whatever the conditions.

5. The importance of loading time

Le loading time of web pages is a key element for a good user experience and also influences SEO ranking. Minimising the amount of JavaScript code in your pages and optimising it can help reduce the time it takes to load and display your content, resulting in a better user experience and better SEO performance.

6. The different methods for optimising JavaScript SEO

Several techniques can be used to improve accessibility and natural referencing compatibility with JavaScript :

Universal rendering (or isomorphic rendering) : This method combines CSR and SSR to provide search engines and users with indexable content while maintaining the interactive benefits of JavaScript.
Optimising JavaScript files : Minimise, compress and group JavaScript files to reduce their size and minimise the HTTP requests needed to load web pages.
Delayed charging : Load only certain parts of the JavaScript when necessary, so as not to slow down the initial loading time unnecessarily.

7. Search engine support for JavaScript

It is important to note that not all search engines are equal when it comes to JavaScript support and execution. Although Google has greatly improved its JavaScript interpretation capabilities over the years, other search engines such as Bing or Yahoo may continue to experience problems analysing content generated by JavaScript. To maximise accessibility and visibility on multiple search platforms, it may be preferable to use a combination of JavaScript SEO methods.

8. SEO JavaScript testing and debugging tools

To check whether your web pages are correctly indexed despite the use of JavaScript, several tools are available:

Google Search Console : By registering for this free tool offered by GoogleYou can obtain information about how Google sees and explores your site.
Tools for webmasters of other search engines : You can also use tools similar to those used by other popular search engines to check how they crawl and understand your JavaScript content.
Leading rendering services : Third-party services exist to help visualise how various browsers and crawlers interpret your site and its JavaScript code.

9. Official documentation on JavaScript SEO

To learn more about JavaScript SEO and the best practices for optimising it, don't hesitate to consult the official documentation provided by the search engines. For example, Google offers a guide for web developers on optimising JavaScript content for their search engines. These guides are a valuable source of information and advice for improving the compatibility between your JavaScript content and natural referencing.

10. JavaScript SEO monitoring and developments

Like all technology, JavaScript and its interaction with SEO are constantly evolving. By keeping up to date with the latest advances in web developmentJavaScript SEO techniques and updates to search engine algorithms, you'll be better prepared to continue offering an optimal experience to users and crawlers.

By taking these 10 key points into account, you can significantly improve the way JavaScript is used in your web pages and applications to ensure better visibility and performance on search engines such as Google, while offering a pleasant and efficient user experience.