Core content visible without JavaScript
Your key content must be present in the initial HTML response. Most AI crawlers do not execute JavaScript.
Why this matters
Search engines like Google run a headless browser that executes your JavaScript before indexing. Most AI crawlers do not. They download the HTML, parse it, and extract text. If your homepage is an empty div that gets filled in by React after a fetch call, the crawler sees nothing.
This is the single biggest reason modern SPAs underperform in AI search. A beautifully built client-rendered site can be completely invisible to ChatGPT or Perplexity even though it ranks on Google.
How to fix it
- — Use server-side rendering. Next.js, Nuxt, SvelteKit, Remix and Astro all do this by default.
- — Or use static generation. Prerender pages at build time.
- — Or use hybrid rendering: SSR the homepage and critical pages, hydrate the rest.
- — If you are stuck on a client-rendered app, add a prerender service like Prerender.io as a fallback for bot user agents.
How to test
The simplest test is curl. If curl shows your headings and main content, a crawler can see them. If it shows an empty body, you have a problem.
curl -s https://yourdomain.com | grep -i "your main headline"