SEO Checker Tool

About

SEO Checker Tool gives you an instant, on-page SEO audit of any webpage in a single click — no signup, no account, no data leaving your browser.

Click the toolbar icon on any page and get a 0–100 SEO score plus a clear breakdown of what's passing, what's a warning, and what's broken. Designed for SEOs, content writers, marketers, web developers, and site owners who want a fast sanity check without opening a heavyweight web tool.

WHAT IT CHECKS

• Title tag — presence and length (30–60 char sweet spot)
• Meta description — presence and length (70–160 chars)
• Headings — H1 count, full H1–H6 outline, empty headings
• Canonical URL, robots meta, hreflang, viewport, charset, language
• Images — missing alt, empty alt, missing lazy-load, oversized
• Links — internal vs external, nofollow, links without anchor text, unsafe target="_blank" without rel="noopener"
• Open Graph and Twitter Card tags
• Schema markup — JSON-LD and microdata types detected
• Content — word count, paragraphs, top keywords by density
• Technical — HTTPS, DOCTYPE, HTML size, scripts, stylesheets, iframes, favicon, web manifest, Apple touch icon

FEATURES

• Instant 0–100 weighted score with pass / warning / issue counts
• 8 organized tabs: Overview, Meta, Headings, Content, Links, Images, Social, Tech
• Light, Dark, and Auto (system) themes
• Compact and expanded popup sizes
• Export full report as JSON
• Copy a clean text summary to clipboard
• Works on any standard https:// or http:// page

PRIVACY-FIRST

• 100% local — analysis runs entirely inside your browser
• No data is sent to any server, ever
• No account, no login, no telemetry, no cookies, no analytics
• No tracking of your browsing history
• Only two permissions: activeTab and scripting (so it can read the page you click on)
• No host permissions, no <all_urls>
• No remote code, no inline scripts — strict Content Security Policy

LIMITATIONS

• Cannot analyze browser-internal pages (chrome://, edge://, about:, chrome-extension://) — open a regular website instead
• Some pages with strict CSPs may block content scripts
• Analyzes the current rendered DOM (so JavaScript-rendered content is included)

Want a deeper, multi-page crawl with backlinks, Core Web Vitals, and historical tracking? Try the Pro web version at https://seochecktool.com

Open source, no ads, no upsells inside the extension itself. Built by Empro IT Solutions.