How search engines parse and interpret JavaScript-generated content before indexing.
Why JCP Matters
JCP is a critical concept for modern SEO because it directly impacts a website’s visibility. In the past, if your content was hidden behind JavaScript, search engines simply couldn’t see it, and it wouldn’t rank. Today, search engines like Google are highly proficient at JCP, but it still requires resources and time. If your website is slow to render or has JavaScript errors, it can cause the crawler to “time out” and miss important content. Understanding JCP is a fundamental part of technical SEO, as it is the process that allows a search engine to see the same content as a human user, which is a prerequisite for ranking.
Across Different CMS Platforms
The management of JCP depends on your CMS and how you build your site.
WordPress
WordPress’s default structure is a perfect example of how to optimize for JCP. It uses standard HTML, so search engines can instantly crawl and index the content. If you’re building a custom front-end with a JavaScript framework on top of WordPress, it is crucial to use a server-side rendering (SSR) approach to ensure all your content is visible to search engines.
Shopify
Shopify’s standard themes are server-side rendered, which means you typically don’t have to worry about JCP. However, if you are using a headless commerce approach with a JavaScript framework, you must implement a server-side rendering or pre-rendering solution to ensure all your product pages are crawled and indexed.
Wix
Wix handles its own JavaScript rendering, so you typically don’t have to worry about JCP. The platform’s system is designed to be SEO-friendly and to ensure that all your content is visible to search engines.
Webflow
Webflow generates clean HTML, so JCP is not a major concern. The platform’s native capabilities ensure that all your content is easily crawlable and indexable, which is a key advantage for SEO.
Custom CMS
With a custom CMS, you have the most control but also the most responsibility. You can build a system that is perfectly optimized for a search engine’s rendering budget by using a server-side rendering (SSR) approach. This is the most effective way to ensure that all your pages are rendered and indexed.
Across Different Industries
The impact of JCP can vary by industry.
E-commerce
E-commerce sites often have thousands of pages, making a limited rendering budget a major issue. It’s crucial to ensure that all your product and category pages are rendered and indexed, so a server-side rendering (SSR) approach is often the best solution.
Local Businesses
Local businesses with a smaller number of pages may not need to worry as much about JCP. However, it is still a best practice to use a server-side rendering (SSR) approach to ensure all your key pages are indexed.
SaaS Companies
SaaS companies often use a JavaScript framework for their marketing pages and dashboards. It is crucial to ensure that their marketing pages are rendered and indexed, while their user dashboards can remain a client-side rendered application.
Blogs
Blogs built with a JavaScript framework can suffer from a limited rendering budget, as a search engine may not get to all of their articles. A great strategy is to use a pre-rendering solution to ensure that all your articles are rendered and indexed.
Do’s and Don’ts of JCP
Do’s
- Do use server-side rendering (SSR). This is the gold standard for JavaScript SEO. It ensures that a search engine crawler always receives a fully-formed HTML page.
- Do use a pre-rendering solution. If you are using a client-side rendering (CSR) approach, a pre-rendering solution is a must.
- Do use Google Search Console. The URL Inspection tool will show you exactly how Google sees your pages.
Don’ts
- Don’t use a pure client-side rendering (CSR) approach. This is the number one mistake and can lead to a page having little to no visibility in search results.
- Don’t block search engines from crawling JavaScript files. A search engine needs to access your JavaScript to properly render the page.
- Don’t use JavaScript to hide your content. This can lead to a penalty and a loss of organic traffic.
Common Mistakes to Avoid
- Failing to use server-side rendering (SSR) or pre-rendering: This is the most common and devastating mistake.
- Having a slow rendering speed: A slow rendering speed can consume your rendering budget and lead to a low indexation rate.
- Having a JavaScript error: A JavaScript error can prevent a search engine from rendering your page, leading to a loss of organic traffic.
FAQs
How is JavaScript Content Parsing different from a regular crawl?
A regular crawl simply downloads a webpage’s HTML code. JavaScript Content Parsing is a second step where the search engine actually runs the JavaScript to see the full content of the page, including any content that is loaded dynamically.
How can I test if a search engine can parse my JavaScript?
The best way is to use the URL Inspection tool in Google Search Console. It will show you a screenshot of how Google sees your page and a list of all the resources it failed to load.
Does a search engine parse JavaScript as a human would?
Yes, Google’s crawler is a headless browser that can execute JavaScript just like a human user’s browser would. This allows it to see and understand the full content of a page, including any dynamic content.
What is the difference between JCP and JavaScript SEO rendering budget?
JCP is the process itself. The rendering budget is the time and resources a search engine allocates to that process. You want to make sure your site is optimized for JCP so you don’t waste your rendering budget.
Can a search engine index content that is only visible after a user scrolls?
Yes. Google can see content that is only visible after a user scrolls, but it is a best practice to ensure that your most important content is above the fold to ensure it is immediately seen and indexed.
