A hreflang checker that follows every link back.

Hreflang fails silently. Google doesn't report most mistakes; it just ignores the tags and shows the wrong version. So we check the things that make it ignore them.

1. 1Valid codes

   ISO 639-1 language, optional ISO 3166-1 region. We catch en-UK, en_US, jp, us-en and friends.

2. 2Absolute URLs

   Full https:// URLs only. Relative paths aren't supported.

3. 3Self-reference

   Each page has to list itself alongside its alternates.

4. 4No duplicates

   One code, one URL. Conflicts between the HTML and the Link header count.

5. 5Alternates load

   Each alternate returns 200, doesn't redirect, isn't noindex, and is canonical to itself.

6. 6Return tags

   Every alternate links back to the page you entered. Without that the pair is ignored.

The matrix puts every page in the set on its own row and every hreflang code from your page in a column. A dot means that page has the code and points it at the same URL your page does. A triangle means it points somewhere else, which usually means the sets were generated from different lists. A dash means the tag is missing.

A healthy set is a solid grid of dots. A row of dashes is a page with no hreflang at all, often a template that never got the tags. A column of dashes is a language most pages forgot about.

The fix is nearly always the same: generate the full tag set from one list, in one place, and output it identically on every version. Redirects inside the set are easy to miss; the Redirect Checker shows each hop.

AI search tools that browse the web pick a page to read and quote. When your language versions are clearly connected, search engines can send a German question to the German page instead of a machine-translated summary of the English one. Hreflang is one of the clearest signals you can give about which page is for whom. Check the rest of each version with the On-Page SEO Checker.