How WebPrerender Crawls and Renders JavaScript Websites?
Tags: webdev, javascript, programming, beginners
Published: 2022-12-28 06:35:12

JavaScript is becoming more and more popular with each passing day, and the stats below will prove it.

As of 2022, there are 1.8 billion websites worldwide, of which 98% use JavaScript in some way.

The increasing acclaim of JavaScript is because it lets developers incorporate functionality into rather static websites. For example, creating dynamic graphs according to data and filtering content.

This makes website visitors' journeys great, but not for search engines. However, you can [**prerender nextJS apps**](https://webprerender.io/next-js/) or other websites to allow search engines to crawl your website seamlessly.


## How do search engines crawl and index websites?


The Internet is the homeland of websites where millions of them are linked to each other. On the other hand, search engines are like directories for finding sites in a structured format.

For this process, search engines need to find websites first, and it is called crawling. A search engine bot or crawler follows a link to a new page and follows the link on that page. As a result, it can discover new web pages and comprehend their relationships.

Moreover, search engines render web pages during crawling.


## How do search engines render websites?


Search engines have experienced several headaches because of the rise in the prevalence of JavaScript. However, nowadays, rendering has become a fundamental process.

After crawling websites, new URLs will be queued up for crawling, and crawled ones will be rendered. Rendering is the process of building a page from all downloaded files and converting (hyper)text to pixels, exactly like browsers.

You can **[prerender HTML pages](https://webprerender.io/)** to speed up the process.

Then, the search engine will take a snap of the result and compare it with the HTML version. Lastly, it returns the page for indexing.


## So, where is the problem?


Even if eminent search engines like Google have figured out crawling and rendering, repeating those processes for billions of web pages daily is troublesome.

Moreover, if someone updates the page, the search engine needs to recrawl that page in order to offer the best search results. As a result, search engines determine a specific number of requests that the bot or crawler will carry out in a specific period of time.


## The solution: Web Prerender


Generally, developers can use any of the three solutions to solve the rendering problem. That is server-side rendering in React, client-side rendering, and prerendering.

In server-side rendering, the burden comes on the server. On the contrary, in client-side rendering, the burden comes on the browser. However, both methods have their issues.

So, the best possible way is prerendering.

When crawlers request a prerendered URL, prerendering caches your page's rendered version and presents it to the search engine crawler. As a result, prerendering will boost the response speed.


## Wrapping up!


As we discussed above, JavaScript is prominent yet troublesome at the same time. However, when you prerender JavaScript, a majority of the issues are solved.

Rendering can take away all of the complexities. Also, search engines can crawl and index your web pages in no time, take profit from the crawl budget, and offer considerable SEO returns. So, you can save money and also boost SEO with prerender JavaScript SEO.