---
title: "How does Lemwatch check hreflang tags? — Lemwatch Help"
description: "Lemwatch validates hreflang clusters, confirms return-tags exist on all variants, and flags invalid locale codes or missing x-default entries."
canonical: "https://lemwatch.com/help/hreflang-monitoring"
source: "https://lemwatch.com"
---

# How does Lemwatch check hreflang tags?

> Lemwatch validates hreflang clusters, confirms return-tags exist on all variants, and flags invalid locale codes or missing x-default entries.

## Quick answer

 We crawl every page in a hreflang cluster, verify each variant lists back to all siblings (return-tags), validate locale codes against ISO 639-1 / 3166-1, and flag missing x-default.

## What we detect

- Broken return-tags (asymmetric hreflang)

- Invalid locale codes (e.g., en-UK instead of en-GB )

- Missing x-default

- Hreflang pointing to noindex or 404 pages

- Mixed absolute + relative URLs

## Where to find it in Lemwatch

 **Site → SEO → Hreflang** — see the cluster graph.

## FAQ

### Do you support HTTP header hreflang?

 Yes — we parse both HTML <link> and Link: headers.

## Related

- Canonical checks

- SEO monitoring overview


## Related

- [Help centre](https://lemwatch.com/help)
- [How does Lemwatch validate canonical URLs?](https://lemwatch.com/help/canonical-url-checks)
- [SEO Health Monitoring](https://lemwatch.com/help/seo-monitoring)
- [How does Lemwatch validate structured data (JSON-LD)?](https://lemwatch.com/help/schema-structured-data-checks)
- [How does Lemwatch track Google indexation?](https://lemwatch.com/help/indexation-tracking)
- [Lemwatch pricing](https://lemwatch.com/pricing)
- [Hreflang tag check](https://lemwatch.com/help/hreflang-tag-check)
- [Heartbeat & Cron Job Monitoring](https://lemwatch.com/help/heartbeat-monitoring)