--- title: Initial HTML contains substantive text description: Many AI crawlers do not execute JavaScript. A single-page app that ships an empty shell and hydrates its content on the client is effectively blank to them, even when a browser-based renderer like Googlebot can see the full page. Server-rendering the main text is what makes a page readable to the widest set of agents. doc_version: 0.2.0 last_updated: "2026-06-10T04:36:50.573Z" --- ## How the check decides The check reads the initial HTML response — the bytes the server returns before any client-side JavaScript runs — clones the ``, removes ` ``` The content only exists after `app.js` runs, so a non-JS agent sees nothing. ## Sitemap Full docs site index: [/sitemap.md](/sitemap.md).