GoSEO – On-Page SEO Checker

About

GoSEO checks on-page SEO instantly. See meta tags, keywords, headings, images, links, schema, and Core Web Vitals for any page.
No logins, no ads, no tracking. Everything runs locally in your browser.

🔧 At a Glance
✓ Meta tags, SERP preview, Open Graph & Twitter cards
✓ Keywords, word counts, density analysis
✓ H1–H6 heading structure
✓ Image analysis (ALT text, size, format)
✓ Link checker (internal/external, nofollow, missing titles)
✓ Script tags & resource hints
✓ JSON-LD structured data viewer
✓ Core Web Vitals (LCP, CLS, FCP, TTFB)
✓ Export data (CSV / ZIP)
✓ Light & dark themes

✅ Instant Overview

SERP & social previews - See how your page appears in Google, Facebook, and Twitter
Essential meta tags - Title, description, canonical, robots, hreflang, favicon with character counts
Core Web Vitals - LCP, CLS, FCP, TTFB metrics for performance tracking
Scripts & resources - All script tags and resource hints (preload, preconnect, dns-prefetch)
Indexability signals - Quick checks for robots.txt and sitemap references


✅ Keywords & Word Analysis

Word count, unique words, reading time, text/HTML ratio
Single words and up to 5-word phrases
Sort by word, count, or density
Real-time search with minimum count filter
Density chart to spot under or over-optimized keywords
Export keyword data to CSV


✅ Headings

Full H1–H6 structure in a clean hierarchy
Spot missing H1s, duplicates, or skipped levels
Click any heading to jump to it on the page
Export all headings (Text/CSV)


✅ Images

See every image on the page
Spot missing ALT text, missing dimensions, oversized files, and outdated formats
Check file size, dimensions, format, and lazy-loading status
Filter to show only images needing attention
Export the full list to CSV or download all images as a ZIP


✅ Links

View total links, unique URLs, internal/external breakdown, nofollow tags, missing titles
Broken link detection runs automatically in the background
Filter by type (internal, external, nofollow, broken)
Click any link to jump to it on the page
Export all link data to CSV


✅ Structured Data (Schema)

View all JSON-LD structured data blocks on the page
See parsed and raw JSON
Export all schemas as JSON


🎯 Built For
✓ SEO consultants doing quick client audits
✓ Content writers optimizing articles
✓ Web developers checking technical implementation
✓ Marketers reviewing landing pages and competitors
✓ Anyone tired of juggling multiple SEO tools

🛡️ Privacy
Everything runs in your browser. No tracking, no data collection, no external requests.

🧑‍💻 Open Source
Fully open source (MIT license). Code is public and transparent on GitHub.