Hreflang / Canonical Validator — User Guide

Fetches a URL and checks its hreflang alternate links and canonical tag against common international SEO pitfalls.

Quick start

1. Enter a URL and click Check.
2. The tool extracts the page's canonical tag and every <link rel="alternate" hreflang="..."> entry.
3. It then fetches each alternate (up to 10) to confirm it links back to the original page — hreflang is supposed to be reciprocal: if page A points to page B, page B should point back to page A.

What gets flagged

• Invalid-looking language codes — anything that doesn't look like en, en-US, or x-default.
• Duplicate hreflang codes — the same code listed more than once on the page.
• Missing self-reference — best practice is for a page to list itself among its own hreflang alternates.
• Missing return link — an alternate that doesn't link back to the page you checked.

Limits

Reciprocity is checked for at most 10 alternates per run, and each check is a live fetch of that alternate page — a slow or unreachable alternate shows as "not checked" rather than failing the whole run.