Open your website, right-click and choose View Page Source. Search that page for your phone number, or for the name of a service you sell. If you can’t find it, neither can ChatGPT.

That one check catches a problem we are seeing more of, especially on sites made quickly with some AI website builders and app builders. The site looks finished in a browser. But the page it sends out is an empty shell, and the words only appear after JavaScript runs on the visitor’s device.

Why can’t AI tools read some websites?

Because most of them don’t run JavaScript. Vercel studied AI crawler traffic across its network and reported that “none of the major AI crawlers currently render JavaScript,” including the crawlers from OpenAI, Anthropic and Perplexity. ChatGPT and Claude fetch JavaScript files but don’t execute them, so “they can’t read client-side rendered content” (Vercel).

The exception Vercel names is Google’s Gemini, which uses Google’s own crawling and does render JavaScript.

Doesn’t Google run JavaScript?

Yes, with a delay. Google says it processes JavaScript sites in three phases, crawling, rendering and indexing, and that a page waiting to be rendered “may stay on this queue for a few seconds, but it can take longer than that.” Google’s own advice is that “server-side or pre-rendering is still a great idea,” because it is faster for people and crawlers, and because “not all bots can run JavaScript” (Google).

So a JavaScript-only site can still show up on Google. It is simply asking every search engine and assistant to do extra work before it can learn what you do, and most assistants won’t.

What does a crawler see on a JavaScript-only site?

We looked at a local contractor’s site built this way. In a browser it has a home page, a page for each service and a page for each town it serves. The HTML each of those pages sends is the same 8 KB file: an empty title, a link to a script, and no words about the business at all. To an assistant that doesn’t run JavaScript, the bathroom remodeling page and the Weirton page are identical and blank.

What should the page source show?

  • A real title with your service and your town, not a blank one.
  • Your words: the services, the towns you serve, your phone number and address.
  • Structured data that tells machines your business name, location and hours. More on how we approach AI visibility.
  • One address for the site. If both the www and non-www versions load as separate copies, search engines have to guess which is real.

How do you fix it?

The fix is in how the site is built, not in a plugin. The pages have to arrive as finished HTML, rendered on the server or built ahead of time, so every crawler reads the same page a person sees. Every site we build works that way, including this one: view the source of this page and the article you are reading is there.

If your site fails the check, the content you already have usually isn’t wasted. It needs a new foundation, with every old URL kept or redirected so you don’t lose what Google has already found. More on rebuilds here.

How do you check your own site in a minute?

  1. Open your home page and choose View Page Source (on a phone, ask someone with a computer).
  2. Search for your phone number.
  3. Search for the name of your main service and your town.
  4. Look at the line that starts with <title>. It should name your business and what you do.
  5. Do the same on one service page.

If any of those come up empty, call us and we’ll tell you what we see.