SEO Audit Tool

About

Enter a URL. The tool fetches the page, along with its robots.txt, sitemap.xml, and llms.txt, and runs 169 checks against it across seven scored categories: Meta Information (27 checks), Content Structure (17), Technical (41), Social & Rich Results (33), Links (13), Accessibility (21), and Performance (17, three of them Core Web Vitals). Every check carries a weight from 1 to 3; a pass earns the full weight, a warning earns half, an error earns nothing. Out comes a 0-100 score with a straightforward verdict: 85 or better is Excellent, 65 or better is Fair, and below that the page Needs Work.

The architecture stays deliberately small. A stateless proxy performs the fetch and hands back the raw material — HTML, response headers, status, timing, size, HTTPS flag. It refuses private and localhost addresses, caps responses at 5 MB, gives up after 15 seconds, and announces itself in its user-agent string as SourceStrongAI-SEO-Audit/1.0. It keeps no copy of anything. From there the work moves into your browser: the DOM is parsed and all seven categories are evaluated and scored client-side. One carve-out stated plainly — the three Core Web Vitals (LCP, CLS, TBT) come from Google's public PageSpeed Insights API, requested straight from your browser; they are lab measurements on the mobile profile, not field data. No accounts, no stored reports.

Two things here are rare in audit tools. First, AI visibility: a check for whether llms.txt exists and follows the expected shape, and a robots.txt read against 15 named AI crawlers — GPTBot, ClaudeBot, and PerplexityBot among them — so you know which agents can reach your content. Second, rendered social previews: rather than only validating tags, the tool draws the card your page produces on X, LinkedIn, Reddit, WhatsApp, and Discord, with notes on each platform's caching quirks.

Each failed or warned check includes a concrete fix — the exact tag to add, the exact header value to set. One button compiles the full list into a structured prompt for an AI coding agent, critical issues grouped first, a verification checklist at the end; another copies a plaintext report tagged line by line. Results get a shareable address, /seo/ plus your URL, so one link re-runs the identical audit for anyone. The tool is free, and this site holds itself to it: our homepage description is budgeted to 160 characters so we pass our own audit.

Highlights

• 169 weighted checks in 7 categories, scored 0-100 with pass, warning, and error counts
• AI visibility: llms.txt validation plus robots.txt access for 15 named AI crawlers
• Social previews drawn for X, LinkedIn, Reddit, WhatsApp, and Discord — not just tag checks
• One-click fix prompt for AI coding agents; every failed check ships a code-level fix
• Stateless proxy, in-browser analysis, shareable /seo/{url} links — free

Who it’s for

Site owners checking their own pages, developers and marketers auditing client work, and indie builders shipping without an SEO budget. It is equally for people who fix sites with AI coding agents: the audit's natural end state is a prompt you paste straight into one, with a separate site-wide checklist prompt when you want the full pass.

Details