# How does Google process JavaScript-heavy websites?

> Google processes JavaScript applications through crawling, rendering and indexing.

A simplified model is:

**Crawl URL → receive response → render when appropriate → execute JavaScript → parse rendered HTML → index**

Googlebot can queue pages with 200 responses for rendering. Google uses a headless Chromium-based rendering system and can parse links from rendered HTML.

This does not mean JavaScript is risk-free. Rendering introduces additional dependencies such as resource accessibility, runtime errors, API availability and correct DOM generation.

Google also notes that server-side or pre-rendering can still be beneficial for speed and reliability.

## Sources

- [Google Search Central — Javascript SEO Basics](https://developers.google.com/search/docs/crawling-indexing/javascript/javascript-seo-basics)

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Answered by Abhinav Krishna (https://www.theseocentral.com/author/abhinav-krishna)
Source: https://www.theseocentral.com/technical-seo-faq/how-does-google-process-javascript-heavy-websites