SEO Sidekick — Free On-Page & AI SEO Toolkit

Free on-page & AI SEO toolkit: broken links, on-page audit, AI/GEO, indexability, hreflang, schema & snippet preview.

SEO Sidekick is a free, private, on-page SEO toolkit that opens as a docked side panel — so the page stays visible right next to your analysis. No account, no sign-up, no analytics. Everything runs locally in your browser. Click the toolbar icon and the panel opens on the current page, following you as you browse. Seven tools in one place: • Broken Link Checker — scans the links on the page and reports their real HTTP status (external links included, not just "unknown"), detects redirects, and exports to CSV. • On-Page Analyzer — title and meta description with length checks, a full heading outline (H1–H6 in document order, with skipped-level warnings), link and image inventories with export, canonical/robots/viewport, Open Graph and Twitter tags, and a main-content word count that ignores nav, header, footer and sidebars so the number reflects the actual article. Structured-data detection and validation across JSON-LD, Microdata and RDFa — with a per-block JSON download. • AI / GEO Readiness — the tool built for AI search. It audits which AI crawlers are allowed or blocked in robots.txt (GPTBot, ClaudeBot, PerplexityBot, Google-Extended, CCBot and more), checks for an llms.txt file, scores how "quotable" your page is for AI answers, and shows keyword density and readability. • Technical & Indexability — a clear "Will Google index this?" verdict that combines the X-Robots-Tag response header, meta robots, canonical, and robots.txt — signals most on-page tools miss — plus a robots.txt and XML-sitemap check (including whether the current page is listed). • Hreflang Validator — real ISO 639-1 language-code validation, self-reference and duplicate checks, and return-tag reciprocity. • Dofollow / Nofollow Highlighter — outlines every link by follow status and internal/external scope, with live counts and a legend. • Snippet Preview — pixel-accurate Google title and description widths, with desktop and mobile truncation points and a live preview card. Privacy first: SEO Sidekick collects no data. There is no backend and no analytics. The only network requests are the checks you run — link status, robots.txt, sitemap, response headers, and hreflang targets — and they go straight from your browser to the site you're analyzing. Built for SEO professionals who want a fast, private on-page and AI-search toolkit — for free.