Technical SEO FAQ · JavaScript SEO & Rendering
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.
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