SEO Analyzer

Paste your page HTML and get an instant on-page SEO report. Checks title, meta description, headings, images, links, Open Graph tags, structured data, and more.

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Free Client-Side Private
Paste your page HTML on the left
and click Analyse SEO
to see the results.
🔒 This tool runs entirely in your browser — your files are never uploaded to any server.

The SEO Analyzer is a free, browser-based tool that checks your page's HTML source against the most important on-page SEO factors and gives you an instant scored report. Paste your full page HTML, click Analyse, and get categorised pass/warning/fail results for basic SEO, content structure, technical settings, social tags, images, and links. All analysis happens in your browser — nothing is uploaded to any server.

Features

Feature Detail
Scored report An overall 0-100 SEO score based on weighted pass/warning/fail results
Basic SEO checks Title tag length, meta description length, canonical URL, robots meta
Content structure H1 presence and count, H2 headings, heading hierarchy, word count
Technical checks Viewport meta, charset declaration, lang attribute, JSON-LD structured data
Social tags Open Graph title, description, image, and URL
Image audit Detects images missing alt attribute or with empty alt text
Link audit Internal and external link counts, links without anchor text
Colour-coded results Green tick (pass), orange exclamation (warning), red cross (fail), grey i (info)
Stats bar Summary of pass/warn/fail counts, word count, image count, and link count
File load Open any .html, .htm, or .txt file directly from your device

How to Use

  1. Open the page you want to analyse in your browser.
  2. Press Ctrl+U (Windows/Linux) or Cmd+Option+U (Mac) to view the page source.
  3. Press Ctrl+A to select all, then Ctrl+C to copy.
  4. Paste the HTML into the HTML source field on the left.
  5. Click Analyse SEO — results appear on the right, grouped by category.
  6. Review each item and use the detail text to resolve warnings and failures.

Alternatively, click Load to open a locally saved .html file.

Checks Reference

Basic SEO

Check Pass condition Notes
Title tag 30-60 characters Under 30 is too short; over 70 is truncated by Google
Meta description 70-160 characters Optimal range is 120-160 characters
Canonical URL <link rel="canonical"> present Prevents duplicate content issues
Robots meta No noindex or nofollow Missing tag defaults to index, follow

Content Structure

Check Pass condition
H1 heading Exactly one H1 present
H2 headings At least one H2 present
Heading hierarchy No skipped heading levels (e.g. H1 → H3)
Word count 300 or more words after stripping scripts and styles

Technical

Check Pass condition
Viewport meta <meta name="viewport"> present
Charset <meta charset> or http-equiv="Content-Type" present
Language attribute lang attribute present on <html> element
Structured data At least one <script type="application/ld+json"> block present

Social (Open Graph)

Tag Pass condition
og:title Present with non-empty content
og:description Present with non-empty content
og:image Present — enables visual social sharing cards
og:url Present — sets the canonical sharing URL

The tool audits every <img> for a missing or empty alt attribute, and every <a href> for presence of anchor text and whether the link is internal or external.

Scoring

The overall score is calculated on a 0-100 scale:

  • Each pass contributes 2 points
  • Each warning contributes 1 point
  • Each fail and info contributes 0 points
  • Score = (total points earned / maximum possible points) x 100
Score range Rating
80-100 Good
50-79 Needs work
0-49 Poor

Frequently Asked Questions

Does this tool fetch my live website?

No. The tool only analyses the HTML you paste into the input field. Nothing is fetched from the internet — all analysis runs locally in your browser.

Why paste HTML instead of entering a URL?

This is a fully client-side tool — it has no server component that can make HTTP requests. Pasting the HTML source gives you the same analysis without requiring server-side infrastructure or dealing with CORS restrictions.

What does the word count check measure?

The tool counts whitespace-separated words in the page body after removing <script>, <style>, and <noscript> content. It reflects the readable text a user and search engine would see, not the raw character count of the HTML file.

How do I get my page's HTML source?

In any desktop browser, open the page and press Ctrl+U (Windows/Linux) or Cmd+Option+U (Mac) to open View Source. Press Ctrl+A to select all, then Ctrl+C to copy. Alternatively, right-click the page and choose "View Page Source".

Does a low score mean my page will rank poorly?

Not necessarily. This tool checks common on-page SEO best practices. Actual ranking depends on many factors including backlinks, site speed, Core Web Vitals, content quality, and competition. Use the results as a checklist, not a ranking prediction.

Will this tool find all SEO issues?

This tool covers the most important on-page HTML factors. It does not check page speed, Core Web Vitals, mobile usability, crawl errors, duplicate content across pages, or off-page factors such as backlinks.

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