RenderPeek · a free tool from ModPageSpeed
See what AI crawlers miss. Optimize the HTML you serve, on your own servers.
Most AI crawlers read your raw HTML and never run your JavaScript, so anything your scripts render is invisible to them. Paste a URL to see the gap. The same self-hosted mod_pagespeed worker that powers this site then optimizes and cleans that HTML inline, on your own servers rather than behind a CDN. Automatically serving a fully-rendered copy to AI agents is on our roadmap.
Free · no signup · one page at a time · renders your page in a headless browser (~5–10s).
Only scan sites you own or are authorized to test. Scanned content is used only to produce this readability result and is not retained or shared beyond that. Your IP address is logged and rate-limited to 20 requests per minute per visitor to prevent abuse. See our Privacy policy.
From We-Amp — built by a mod_pagespeed maintainer.
Which AI crawlers render JavaScript?
The major AI crawlers fetch your raw HTML and do not run your scripts. Only Google’s stack renders JavaScript today. This reflects crawler behavior in 2026 and can change, so re-scan to confirm what an agent sees now.
| Crawler | Used by | Renders JavaScript? |
|---|---|---|
| GPTBot | ChatGPT | No — static HTML only |
| ClaudeBot | Claude | No — static HTML only |
| PerplexityBot | Perplexity | No — static HTML only |
| Googlebot | Google / Gemini | Renders JS |
Frequently asked questions
Can AI crawlers read JavaScript-rendered content?
Most cannot. GPTBot (ChatGPT), ClaudeBot, and PerplexityBot fetch raw HTML and do not execute JavaScript, so content that only appears after your scripts run is invisible to them. Google’s Gemini is the exception — it reuses Googlebot’s rendering.
Which AI crawlers render JavaScript?
As a rule, only Google’s stack (Gemini via Googlebot) renders JavaScript. GPTBot, ChatGPT-User, ClaudeBot, and PerplexityBot read static HTML only. If your content is client-rendered, those agents see a near-empty page.
How do I check what an AI crawler sees on my page?
Disable JavaScript and reload — what remains is roughly what a non-rendering crawler reads. Or paste your URL into the scanner above: it shows the raw-HTML vs rendered token counts side by side.
How do I make my site readable to AI agents?
Serve the meaningful content in the initial HTML response (server-side rendering or pre-rendering). A self-hosted optimizer like mod_pagespeed reduces page weight and cleans markup, which helps both browsers and machine readers.
Does llms.txt make my site AI-readable?
No. llms.txt is an optional hint file; it does not fix content that is invisible because it requires JavaScript to render. Readability still depends on the content existing in the HTML the agent fetches.