SEO Audit

On-page SEO audit with per-check fixes; deep scan adds Lighthouse + broken-link detection.

A free on-page SEO site checker. Enter a URL and Zapbox fetches the page server-side, parses the HTML, and checks the title & meta description (and their length), H1 & heading structure, canonical, meta robots, Open Graph & Twitter cards, JSON-LD structured data, image alt text, viewport, charset, lang, word count, internal/external links, HTTPS, and robots.txt / Sitemap — then gives a 0–100 score with a fix suggestion per check. Switch to Deep scan to additionally run Lighthouse (performance / accessibility / best-practices / SEO scores plus Core Web Vitals) and detect broken links on the page. Public URLs only.

How to use

  1. Paste the URL to check (https:// is optional).
  2. Click Scan — the server fetches and analyzes the page.
  3. Read the overall score and the per-check results grouped into Meta / Headings / Social / Structured data / Content / Technical.
  4. For items flagged warn or fail, apply the suggested fix.

FAQ

Why fetch server-side instead of in the browser?
Browsers cannot read another site’s HTML due to the same-origin policy (CORS). Fetching from the Zapbox server is the only way to get the full page to analyze; the page is used and discarded, not stored.
Does it include performance (Lighthouse), broken links, or ranking?
Basic scan focuses on the page’s on-page elements; Deep scan additionally runs Lighthouse (performance / accessibility / best-practices / SEO scores plus Core Web Vitals) and checks the page for broken links (~20–40s). SERP keyword ranking is still not included (it needs a paid data source).
Can it scan internal or local addresses?
No. For safety (SSRF protection), URLs that resolve to private, loopback or other non-public addresses are rejected.

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