GeezerVison is showing watchthis.dev — Free JavaScript SEO Checker: Raw vs Rendered HTML

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JavaScript SEO Checker: See What Google Sees

Compare the HTML your server sends with the DOM produced after JavaScript runs. Find rendering gaps before they affect search indexing and AI crawler visibility.

Public URLs only. Most checks finish in 20–30 seconds.

How It Works

Three steps to uncover what search engines actually see

1. Fetch Raw HTML

We request your page and capture the initial HTML response — exactly what a crawler sees first.

2. Render with JavaScript

We run your JavaScript in a real browser environment and wait for the DOM to settle.

3. Compare & Report

We diff the raw and rendered versions, flagging critical SEO elements that changed or disappeared.

What the JavaScript SEO Checker detects

WatchThis checks whether important SEO elements are present in the initial HTML response or appear only after JavaScript executes. The report highlights differences that may affect crawling, indexing, link discovery and machine-readable metadata.

Title & Meta Tags

Verify title, description, canonical, and robots meta are present in raw HTML

Missing Content

Detect headings, links, and text that only appear after JavaScript runs

Structured Data

Check if JSON-LD schema is in raw HTML or added client-side

JavaScript Errors

Surface runtime errors that might prevent rendering

Redirect Chains

Track HTTP redirects and identify unnecessary hops

Internal Links

Compare link counts before and after rendering

See It In Action

Clear, actionable insights with severity levels

example.com

SEO Health Score: 70 · MEDIUM RISK

70/100

Title missing in raw HTML

Critical: Title only appears after JavaScript renders

H1 count changed

Raw: 0 headings → Rendered: 1 heading

Canonical tag present

Found in raw HTML with correct URL

WatchThis uses a real Chromium browser to compare initial HTML with the rendered DOM. It is a diagnostic tool, not an exact replica of Google Search infrastructure.

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