Content in the HTML

View source on your homepage (the raw HTML, not the browser's element inspector) shows almost none of your words: an empty element like <div id="root"></div> and a list of script tags. Your text only appears once those scripts run.

In search engines

Google renders JavaScript, but content that's already in the HTML is indexed without waiting and can't be lost to a script error.

In AI assistants

The crawlers behind ChatGPT search, Claude and Perplexity don't document that they run JavaScript. If your words only appear after it runs, they may see an empty page.

We fetch your homepage once and count the readable words in the HTML. 80 or more words passes and earns 2 of 2 points. Fewer than 80 words with an empty app container (such as <div id="root"></div>) fails and earns 0. Fewer than 80 words without an empty container earns 1 of 2.

Render pages on the server (SSR) or at build time (static generation). Frameworks like Next.js, Astro, Nuxt and TanStack Start do this out of the box.

• CM-102 Inner pages have their own content: Runs the same word count on up to three inner pages. This check tests only your homepage.
• CM-104 Search and AI search crawlers allowed: Checks whether robots.txt lets search crawlers fetch your homepage at all. This check looks at what the HTML holds when they do.
• CM-903 Firewall treatment of AI crawlers: Compares how your server answers an AI crawler with how it answers our scanner. This check counts the words in the page our scanner gets.

• Google: Understand JavaScript SEO basics (opens in a new tab)
• OpenAI: Overview of OpenAI crawlers (opens in a new tab)
• Anthropic: Does Anthropic crawl data from the web? (opens in a new tab)
• Perplexity: Perplexity crawlers (opens in a new tab)