Back to blog

How to check what Google and AI crawlers see on your website

A practical guide to checking what Google and AI crawlers see on your website, from curl tests to crawler-readable HTML checks.

Guides
Jun 23, 2026
6 min read

One of the most common mistakes on JavaScript-heavy websites is assuming that a working browser preview proves crawler access. It does not.

If you want to know what search engines and AI crawlers see, you need to test the response path directly. The good news is that you can do that without rebuilding anything first.

Quick answer

Do not guess from the browser preview. Check the HTML that search engines and AI crawlers receive. If bots get a thin shell and the rendered page has real content, you have a technical visibility gap.

What you are checking for

You are not only checking status codes. A page returning 200 is not enough.

You want to know:

  • Does the crawler request succeed?
  • Does it receive readable text?
  • Does the response include a title, headings, and useful page copy?
  • Is the page still a thin HTML shell?

That is the difference between “reachable” and “understandable.”

The fastest manual test

Normal browser-style request

Terminal
1curl -L https://yourwebsite.com > browser.html

Googlebot-style request

Terminal
1curl -L -A "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)" https://yourwebsite.com > googlebot.html

GPTBot-style request

Terminal
1curl -L -A "Mozilla/5.0 (compatible; GPTBot/1.0; +https://openai.com/gptbot)" https://yourwebsite.com > gptbot.html

ClaudeBot-style request

Terminal
1curl -L -A "Mozilla/5.0 (compatible; ClaudeBot/1.0; +https://anthropic.com)" https://yourwebsite.com > claudebot.html

PerplexityBot-style request

Terminal
1curl -L -A "Mozilla/5.0 (compatible; PerplexityBot/1.0; +https://perplexity.ai)" https://yourwebsite.com > perplexitybot.html

What a good result looks like

A good result contains:

  • a real page title
  • headings
  • readable text
  • internal links
  • metadata

You should be able to search the response for content that proves the page topic:

Terminal
1grep -i "<h1" googlebot.html
2grep -i "your main headline" googlebot.html
3grep -i "canonical" googlebot.html
4grep -i "og:title" googlebot.html

What a bad result looks like

Bad crawler output often looks like this:

HTML
1<div id="root"></div>
2<script src="/assets/app.js"></script>

Or it returns only a tiny amount of text that is not enough to explain the page.

That is the core technical issue Prerender Buddy is meant to fix.

Check the raw HTML, not only the rendered browser

Many teams only inspect the rendered page after JavaScript runs. That is useful for UX, but it does not answer the crawler question.

A screenshot proves that the page looks finished in a browser. It does not prove that crawlers received the same content in HTML. For JavaScript-heavy sites, the important comparison is raw HTML versus rendered HTML.

Instead, compare:

  1. Initial raw HTML
  2. Bot-style request output
  3. Visitor-rendered output

If the visitor-rendered page has thousands of readable characters and the crawler response has only a few dozen, you likely have a real crawler visibility problem.

Check more than one bot

Different bots behave differently. Googlebot, Bingbot, GPTBot, ChatGPT-User, ClaudeBot, and PerplexityBot are not identical.

That means a site can look acceptable to one crawler and still fail for another.

At a minimum, test:

  • Googlebot
  • Bingbot
  • GPTBot
  • ChatGPT-User
  • ClaudeBot
  • PerplexityBot

Other useful checks

Beyond raw text length, look for:

Page title

If the bot response has no useful title, the page is harder to interpret.

Meta description

Not a ranking promise, but still a useful context signal.

H1 and headings

If the crawler output has no heading structure, the page topic may be weakly expressed.

Structured data

If you use JSON-LD, confirm it is present in the crawler response.

Open Graph tags

Useful for previews and general metadata consistency.

Who this is for

  • SaaS founders with already-shipped JavaScript websites
  • React, Vite, Vue, Lovable, Bolt, or Base44 users
  • SEO freelancers checking crawler-readable HTML
  • Agencies maintaining client sites without rebuilding them

Raw HTML vs rendered HTML example

A client-rendered page can initially look like this:

HTML
1<div id="root"></div>
2<script src="/assets/app.js"></script>

After JavaScript runs, the browser may show the real page:

HTML
1<h1>Actual page headline</h1>
2<p>Readable page copy that explains what the page is about.</p>
3<a href="/pricing">View pricing</a>

The crawler question is which version search engines and AI crawlers receive.

Step-by-step crawler check

  1. Test the raw HTML response.
  2. Test a Googlebot-style request.
  3. Test GPTBot, ClaudeBot, and PerplexityBot-style requests.
  4. Compare how much readable text each response contains.
  5. Check whether titles, headings, metadata, schema, canonicals, and internal links are present.
  6. Decide whether the issue is content, metadata, routing, access rules, or a rendering gap.

The most useful signal is not whether the page returns HTTP 200. It is whether the response gives search engines and AI crawlers enough readable HTML to understand the page.

Where manual tests fall short

Manual curl checks are useful, but they are still snapshots. They do not show whether:

  • real crawler traffic reached your rendering layer
  • the response was served from cache
  • one hostname works while another does not
  • production requests are still arriving as thin HTML

That is why a dedicated visibility checker and crawler logs are useful after initial diagnosis.

Available options after you confirm the problem

If bots are receiving thin HTML, the options are usually:

  • move to SSR
  • export static pages
  • add prerendering for crawler traffic

If the site is already shipped and the goal is to fix crawler-readable HTML without a rebuild, prerendering is often the most practical path.

When Prerender Buddy helps

Prerender Buddy helps when:

  • your browser looks fine
  • crawler HTML is thin
  • you want search engines and AI crawlers to receive rendered HTML
  • you do not want to rebuild the site right now

It is especially useful for React, Vite, Vue, Lovable, Bolt, Base44, Netlify, Vercel, and similar client-rendered setups.

Free tools for this check

You may not need Prerender Buddy if

  • Server HTML is already complete.
  • Static pages crawl correctly.
  • You are already rebuilding with SSR or static generation.
  • You only need an audit, not a rendering fix.

Final recap

How to check what Google and AI crawlers see on your website comes down to what search engines and AI crawlers actually receive from your site.

Prerender Buddy does not guarantee rankings or AI citations. It helps with one specific technical problem: making sure crawlers receive readable rendered HTML instead of a thin JavaScript shell.

The first step is to check what bots see.

Check your website

Check what crawlers see to test whether the site sends readable HTML to search engines and AI crawlers.