# What happens between Google's initial HTML fetch and JavaScript rendering?

> The initial HTTP response may contain complete content or only an application shell.

Example:

`<div id="app"></div>
<script src="/app.js"></script>
`
The rendering system can execute JavaScript and produce:

`<h1>Technical SEO Course</h1>
<a href="/courses/technical-seo">Learn more</a>
`
Google can then use the rendered output for indexing and discover additional links.

This is why comparing **raw response HTML** with the **rendered DOM** is valuable during a JavaScript SEO audit.

## 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/what-happens-between-google-s-initial-html-fetch-and-javascript-rendering