Seo Score

SEO Score — Instant On-Page SEO Analyzer for Any Webpage

Analyze any webpage's SEO in one click. SEO Score runs 37 professional-grade checks across 6 categories, scores the page out of 100, and gives you clear, actionable recommendations to fix every issue — all without leaving your browser.

No accounts. No subscriptions. No data sent anywhere. Everything runs client-side, directly in your browser.

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WHY SEO SCORE?

Most SEO tools want your email, your credit card, or your patience while they spin up a server somewhere to crawl a page you're already looking at. SEO Score takes a different approach: it reads the page already loaded in your tab, runs every check locally, and gives you a score in milliseconds. No network requests. No cloud processing. No waiting.

Whether you're a developer shipping a site, a content writer checking your latest post, a marketer auditing a landing page, or an SEO professional running a quick sanity check — SEO Score gives you the answer instantly.

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WHAT YOU GET

One click opens a dark, professional interface showing:

A score out of 100 displayed in an animated ring, color-coded: green for 80+, amber for 50–79, red for below 50. You know instantly where you stand.

Six category breakdowns with progress bars and fraction scores so you see exactly which areas need attention: Meta Tags, Headings, Content, Social Media, Technical, and Performance.

37 individual checks — each shows a pass, warn, or fail status with the actual value found on the page and a specific recommendation for how to fix it. No vague advice. Every recommendation is tied to what the check actually found.

The worst-performing category auto-expands so you see the most critical issues first. Click any category bar to jump to its detail section. Collapse and expand as you work through each issue.

Analysis time displayed in the footer in milliseconds.

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EVERY CHECK — IN DETAIL

SEO Score runs 37 checks organized into 6 categories. Points add up to 100.

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META TAGS — 20 Points (8 checks)
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Covers the foundational HTML metadata that search engines read first when crawling your page.

Title Exists (4 pts) — Verifies a non-empty title tag is present. The title tag is the single most important on-page SEO element. It appears in search results, browser tabs, and social shares.

Title Length (4 pts) — Measures character count. Pass: 30–60 chars. Warn: 20–29 or 61–70. Fail: outside range. Search engines truncate titles beyond 60 characters.

Meta Description Exists (3 pts) — Checks for a non-empty meta description. The description appears as snippet text in search results and directly affects click-through rate.

Description Length (3 pts) — Pass: 120–160 chars. Warn: 80–119 or 161–200. Fail: outside range. Google typically displays 150–160 characters on desktop.

Canonical URL (2 pts) — Checks for link rel="canonical". Without it, you risk splitting ranking power across duplicate pages.

Meta Robots (1 pt) — Reads meta robots for noindex/nofollow directives. A noindex tells search engines not to index the page — critical if unintentional.

Viewport Meta (2 pts) — Checks for viewport with width=device-width. Essential for mobile responsiveness. Google uses mobile-first indexing, so this directly impacts rankings.

Charset (1 pt) — Verifies character set declaration via meta charset or http-equiv. Without it, browsers may misinterpret special characters.

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HEADINGS — 15 Points (4 checks)
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Evaluates heading structure (H1–H6) for content hierarchy and accessibility.

H1 Exists (5 pts) — Pass: exactly one H1. Warn: two or more. Fail: none. The H1 is the primary heading and should clearly describe the page's main topic.

H1 Length (3 pts) — Pass: 20–70 chars. Warn: 10–19 or 71–100. Fail: outside range. An effective H1 is concise but descriptive.

Heading Hierarchy (4 pts) — Checks for skipped heading levels (e.g., H2 to H4). Pass: none skipped. Warn: one skip. Fail: two or more. Proper hierarchy helps search engines and screen readers.

Heading Count (3 pts) — Pass: 2–15 headings. Warn: 1 or 16–30. Fail: 0 or 30+. Too few means no structure; too many dilutes significance.

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CONTENT — 20 Points (6 checks)
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Evaluates substance, linking, and image optimization.

Word Count (5 pts) — Pass: 300+ words. Warn: 100–299. Fail: under 100. Thin content struggles to rank because it lacks substance for search engines to evaluate.

Internal Links (3 pts) — Counts same-domain links. Pass: 3+. Warn: 1–2. Fail: 0. Internal links distribute link equity and help crawlers discover pages.

External Links (2 pts) — Counts links to other domains. Pass: 1+. Fail: 0. External links to authoritative sources signal well-researched content.

Images Alt Text (5 pts) — Checks percentage of images with non-empty alt attributes. Pass: 100%. Warn: 50–99%. Fail: under 50%. Critical for accessibility and image search traffic.

Has Images (2 pts) — Pass: 1+ images. Fail: none. Pages with images have lower bounce rates and can appear in image search.

Anchor Links Valid (3 pts) — Verifies in-page anchor links (#) point to existing IDs. Pass: all resolve. Warn: 1 broken. Fail: 2+ broken.

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SOCIAL MEDIA — 10 Points (6 checks)
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Checks Open Graph and Twitter Card meta tags that control social share previews.

og:title (2 pts) — The title shown when shared on Facebook, LinkedIn, and other Open Graph platforms.

og:description (2 pts) — The description text in social share previews.

og:image (2 pts) — The preview image for social shares. Posts with images receive significantly more engagement.

og:url (1 pt) — Canonical URL for shared content, preventing share counts from splitting across URL variations.

twitter:card (1.5 pts) — Tells Twitter how to display your content (summary, summary_large_image, etc.).

Twitter Meta (1.5 pts) — Checks for both twitter:title and twitter:description. Pass: both present. Warn: one only. Fail: neither.

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TECHNICAL — 20 Points (8 checks)
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Covers protocol security, structured data, language declarations, and other factors search engines evaluate under the hood.

HTTPS (4 pts) — Pass: HTTPS. Fail: HTTP. Google has used HTTPS as a ranking signal since 2014 and Chrome marks HTTP pages as "Not Secure."

Structured Data (4 pts) — Checks for valid JSON-LD blocks. Structured data enables rich snippets in search results, dramatically improving click-through rates.

Language Attribute (3 pts) — Checks the lang attribute on the HTML element. Pass: valid language code. Warn: empty. Fail: missing. Essential for international SEO.

Hreflang (2 pts) — Checks for alternate language link tags. Single-language sites with a lang attribute pass automatically.

Favicon (2 pts) — Checks for a favicon link. Appears in tabs, bookmarks, and search results. A missing favicon looks unprofessional.

URL Structure (2 pts) — Analyzes URL for lowercase, hyphens, no double slashes, no file extensions, reasonable query length. Pass: clean. Warn: 1 issue. Fail: 2+.

Doctype (1 pt) — Verifies DOCTYPE declaration to prevent quirks mode rendering.

Duplicate IDs (2 pts) — Scans for duplicate ID attributes. Pass: none. Warn: 1–3. Fail: 4+. Duplicates break JavaScript, accessibility, and crawling.

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PERFORMANCE — 15 Points (5 checks)
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Evaluates client-side performance signals tied to user experience and Core Web Vitals.

DOM Size (4 pts) — Counts HTML elements. Pass: under 1500. Warn: 1500–3000. Fail: 3000+. Bloated DOMs slow rendering and degrade interaction responsiveness.

Inline Styles (3 pts) — Counts elements with style attributes. Pass: under 10. Warn: 10–50. Fail: 50+. Inline styles increase payload and prevent caching.

Render-Blocking Scripts (3 pts) — Counts head scripts without async/defer/module. Pass: 0. Warn: 1–2. Fail: 3+. These block rendering and hurt First Contentful Paint.

Image Dimensions (3 pts) — Checks for explicit width/height on images. Pass: all specified. Warn: 50%+. Fail: under 50%. Missing dimensions cause Cumulative Layout Shift (CLS).

Deprecated HTML (2 pts) — Scans for center, font, marquee, blink, strike, big, tt, frame, frameset, applet. Pass: none. Warn: 1–3. Fail: 4+.

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HOW TO USE

1. Navigate to any webpage you want to analyze
2. Click the SEO Score icon in your Chrome toolbar
3. View your score, category breakdowns, and individual check results
4. Click any category bar to jump to its detailed results
5. Read the recommendation for each failing check
6. Fix, reload, re-check

No setup. No configuration. No onboarding.

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PRIVACY AND PERMISSIONS

SEO Score requests only two permissions:

activeTab — Access the current tab only when you click the icon. Cannot read tabs you haven't activated it on.

scripting — Inject the analysis script into the current page. The script reads the DOM, runs checks, and returns results. That's all.

No data collected. No data transmitted. No analytics. No tracking. No cookies. No external requests. Zero network calls. Every byte of processing happens locally. Your browsing data never leaves your machine.

The analysis script includes a double-injection guard. All page-extracted values are rendered using textContent, not innerHTML, preventing cross-site scripting. Built on Chrome Manifest V3.

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WHO IS SEO SCORE FOR?

Web Developers — Quick SEO check before pushing to production. Catch missing meta tags, broken heading hierarchies, and accessibility issues. The dark, monospace interface fits alongside your dev tools.

Content Writers — Verify title length, meta description, word count, heading structure, and image alt text without switching tools.

SEO Professionals — Fast first-pass audit on any page. Category breakdowns tell you where to focus. Run it on competitor pages to benchmark.

Marketing Teams — Audit landing pages before campaigns. Verify Open Graph and Twitter Card tags. Check canonical URLs.

Freelancers and Agencies — Demonstrate SEO value to clients with a clear visual score. Re-run after fixes to show improvement.

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SCORING SYSTEM

100 points total across six categories:

Meta Tags: 20 pts — foundational metadata search engines read first
Headings: 15 pts — content structure and hierarchy
Content: 20 pts — substance, links, images, and optimization
Social Media: 10 pts — Open Graph and Twitter Card tags
Technical: 20 pts — HTTPS, structured data, language, doctype
Performance: 15 pts — DOM size, render-blocking resources, layout stability

Score ranges:
80–100: Good — follows SEO best practices
50–79: Needs Work — notable issues to address
Below 50: Poor — significant problems need immediate attention

Checks award full points for pass, partial for warning, zero for failure.

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THE INTERFACE

Dark theme designed to look like a developer tool. Dark background, surface elevation, muted borders, high-contrast text, monospace fonts for scores and data.

Animated SVG score ring, color-matched to range. Category rows with label, progress bar, fraction. Collapsible detail sections — worst auto-expands. Status characters: green + pass, amber ~ warning, red ! failure. Each check shows name, value found, and fix recommendation.

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TECHNICAL DETAILS

Chrome Manifest V3. No background worker. No persistent scripts. Analysis runs on-demand when you click the icon, on the active tab only.

Four files. No libraries, frameworks, build tools, or dependencies. Pure vanilla JavaScript.

DOM analysis sends results via Chrome runtime messaging. Popup renders with createElement only — never innerHTML. Non-analyzable pages show a clear error.

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FAQ

Does it send my data anywhere?
No. Zero network calls. No analytics, no tracking.

Does it work on any website?
Any HTTP/HTTPS page. Cannot analyze chrome://, about://, extension pages, or Chrome Web Store.

How accurate is it?
Checks the same on-page factors professional tools check. Focuses on client-side DOM — does not check server-side factors.

Can I re-run the analysis?
Close popup, click icon again. Reload the page for a clean re-run.

Why is my score low on a well-ranking page?
Ranking depends on backlinks, domain authority, and engagement. SEO Score measures on-page factors only.

Does it check page speed?
It checks performance indicators — DOM size, render-blocking scripts, image dimensions, deprecated HTML. Not actual load times.

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Version 1.0.0