Understanding Pre-rendering in SEO
Pre-rendering is the process of preloading everything on the page for viewing by a web crawler. The pre-rendering service intercepts a page request to establish whether a bot is the user agent viewing your site. Therefore, if the user agent is a bot, the pre-render middleware sends a cached version of your site. So, display the page with all the JavaScript, images, etc., making sure they are rendered statically.
Therefore, if the user agent is not a bot, everything loads normally. The pre-render service is only used to optimize the bot experience.
Pre-rendering and Google
Some time ago, Google recommended using the AJAX_escaped_fragment_ crawl schema. Unfortunately, this method has been since deplored. However, it appears that some services continue to operate it, e.g. https://prerender.io/. The good news is that websites using prerender.io are indexed in SERP.
How Prereder.io works
Prerender.io is a leader in pre-rendering services. The service runs JavaScript in a browser, saves static HTML code, and returns static HTML code to crawlers. Nowadays, web developers build websites using JavaScript frameworks like Angular, React, Backbone. So, they need JS Executor to display the content. Search engines and social networks crawl your site, not just browsers and real users. However, while crawling your website, they see the JavaScript tags and not the content.
While Google and bots have improved and can crawl pages more efficiently today, your SEO score often drops. The JavaScript executor can be costly, and pages are added to a queue to be crawled a second time by a JS-compatible crawler. This second run can take several days or even weeks. Thus, it can have a grave impact on all your SEO efforts. This is a common trend in SEO when a crawler visits the site to serve pre-rendered HTML pages.
Should we pre-render everything?
The answer is simply no. However, it is advisable to use pre-rendering if your site is a Single Page Application (SPA) and requests to be available for bots to crawl. When content resides behind a login screen, pre-rendering thus becomes redundant, as bots will never pass the first login screen. Additionally, there is no need for pre-rendering your site if all of the content is already a static HTML page and not a JavaScript-enabled SPA.
Benefits of Pre-rendering in SEO
Pleasing Google and Human users
Prerender.io middleware detects when Google visits your website and produces an easy-to-navigate version. You can control the experience of human users when they visit your site because they can see the dynamic JavaScript version.
Highly rated by Google and Bing
Google and Bing search engines offer dynamic rendering solutions to solve JavaScript rendering issues. Indeed, the Google docs specifically recommend pre-rendering with Prerender.io. You can focus more on development and leave SEO to marketers.
Very reliable, simple, and expandable service
The installation of the service is very quick and promises unmatched service commitment at all times.
