JavaScript Rendering Test
See how much content a page only shows after JavaScript runs.
Powered by Geekflare Web Scraping API
Why Raw HTML and Rendered HTML Differ
Modern websites often build their content with JavaScript frameworks like React, Vue, or Angular. The first response from the server can be little more than an empty <div id="root">. The actual content only appears after the browser downloads and runs JavaScript to fill it in.
This is important for scraping. A plain HTTP request (curl, requests, a basic crawler) only sees the raw HTML. If a site depends on JavaScript for its main content, that plain request comes back nearly empty.
What This Tool Does
Enter a URL and this tool fetches it two ways:
- Raw — a plain, non-rendered request, the same as a basic scraper would make.
- Rendered — the fully rendered page, using the Geekflare Web Scraping API with JavaScript execution enabled.
It then compares word count, links, images, and headings between the two, and tells you whether this page needs JavaScript rendering to scrape properly.
How to Read the Results
- No significant difference — the raw HTML already has most of the content. A plain request or lightweight scraper is enough.
- Rendering adds X% more content — the page depends on JavaScript. You'll need a scraper that executes JavaScript, such as Geekflare's Web Scraping API.
Common Use Cases
- Deciding whether a scraping project needs a headless browser or can get by with simple HTTP requests
- Debugging why a scraper is returning empty or incomplete data
- Checking whether your own site's content is visible to crawlers that don't execute JavaScript
Frequently Asked Questions
Raw HTML is exactly what the server sends back on the first request what a basic crawler or curl would see. Rendered HTML is what's in the page after a browser has executed all of its JavaScript.
If a site relies on JavaScript to load its main content, a plain HTTP request will return a mostly empty page. You'd need a scraper that executes JavaScript like a headless browser to get the real content.
This tool flags a page as JavaScript-dependent when rendering adds at least 20% more visible text than the raw HTML, or when the raw HTML has very little text to begin with.
Need this at scale? Try the Geekflare API.
One API key for scraping, search, screenshots, DNS, PDF, and more.
curl -X POST https://api.geekflare.com/webscraping \
-H "x-api-key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"url":"https://example.com"}'