Content readable without JavaScript

What we check

We compare two versions of the home page:

1. the delivered HTML, the way the server sends it, without any script running,
2. the finished page in the browser, after all scripts have run.

If less than half of the visible text is already in the delivered HTML and more than 500 characters are missing, there is a warning. Below 20 % it is a serious defect. If we recognise a JavaScript framework such as React, Vue or Angular, we name it in the report.

This check counts for little, at most 5 of 100 points in the area. For visibility in AI services it is nevertheless fundamental.

Why it matters

Modern websites are sometimes assembled entirely in the browser: the server sends an almost empty page and a large script that inserts the content only afterwards. For people with a current browser this looks the same.

For machines it does not:

• AI crawlers of ChatGPT, Claude, Perplexity and others do not, as a rule, run JavaScript. They read only what is in the HTML. With a pure JavaScript page they may see only "Please enable JavaScript".
• Google runs JavaScript, but in a second step, with a delay and not always completely.
• Previews on social media and messengers are often empty.
• Slow smartphones show the content later, because the script first has to load and run.

How to fix it

The text must be created on the server, not only in the browser. There are several ways:

Server-side rendering (SSR)

The framework builds the page on the server and delivers finished HTML. After that JavaScript in the browser takes over the interaction.

• React: Next.js or React Router (formerly Remix)
• Vue: Nuxt
• Angular: Angular SSR
• Svelte: SvelteKit

Static pages

For websites that rarely change, a generator such as Astro, Eleventy, Hugo or Next.js in export mode produces finished HTML files on publishing. This is fast, secure and readable for all machines.

Pre-rendering

If the website cannot be rebuilt, a pre-rendering service can cache the finished page for crawlers. This is a transitional solution.

Individual content

Often only part is affected, such as reviews from a widget, a job portal or a booking form. Important texts such as services, location and contact you should additionally have as normal text on the page.

How to check it yourself

Open the website and choose "View page source" (not "Inspect"). Use Ctrl+F to search for a sentence from the main text. If you do not find it, it arises only through JavaScript.

Frequently asked questions

Google does run JavaScript. Why is it still a problem?

Google can, with a delay and not always completely. Most AI crawlers read only the delivered HTML, though. What appears only through a script does not exist for them.

Does this affect website builders?

Rarely. Wix, Squarespace and Jimdo deliver the text in the HTML today. Mainly affected are individually developed websites with React, Vue or Angular and some shop and booking systems.