SERP.tools

Hreflang Checker

18 automated hreflang checks — instant and deep

Enter any URL to fetch and parse its hreflang tags. Run 11 instant checks plus 7 deep checks — including return tag verification, noindex conflicts, and html lang mismatches on every referenced page.

Need to create or fix your hreflang tags?

Build tags with BCP 47 validation, 5 presets, and HTML/XML/HTTP header output. → Hreflang Tag Generator

The 18 Checks

11 run instantly on page fetch. 7 more require fetching each referenced URL.

1 Instant No hreflang tags found Info
2 Instant Invalid language code Error
3 Instant Invalid region code Error
4 Instant Missing self-referencing tag Error
5 Instant Missing x-default Warning
6 Instant x-default used multiple times Error
7 Instant Duplicate language codes Error
8 Instant Relative URLs Error
9 Instant HTTP/HTTPS inconsistency Warning
10 Instant html lang attribute mismatch Warning
11 Instant Empty href attribute Error
12 Deep HTTP status — non-200 Error
13 Deep Redirect detected Warning
14 Deep URL has noindex tag Error
15 Deep URL blocked by robots.txt Error
16 Deep Missing return tag Error
17 Deep Canonical conflict Warning
18 Deep html lang mismatch on referenced pages Warning

Why These Checks Matter

Hreflang errors are silent — Google ignores invalid implementations without reporting them in Search Console.

Missing return tags

The most commonly broken rule. Every page you reference must reference you back. Google will silently discard the entire hreflang set if bidirectional links are missing.

Noindex on referenced pages

If Google cannot index a page it cannot verify its hreflang tags, making the annotation unreliable. Any referenced page that is noindexed or robots-blocked breaks the chain.

html lang vs hreflang

While Google does not use the html lang attribute for language detection, a mismatch between html lang and hreflang code is a strong signal of a copy-paste error in your CMS template.

Frequently Asked Questions

What is the most common hreflang error?

Missing return tags. If page A references page B in its hreflang set, page B must also reference page A. When this bidirectional link is missing, Google may ignore the entire hreflang set without reporting an error in Search Console.

Will Google show a hreflang error in Search Console?

Google Search Console does report some hreflang issues, but many silent failures — like missing return tags or invalid codes — are ignored by Google rather than reported. This tool checks all 18 conditions including ones Search Console does not flag.

Why does a noindexed page cause hreflang issues?

Google cannot verify hreflang annotations on pages it cannot index. If a page referenced in your hreflang set has a noindex tag, Google cannot crawl and confirm the return tag, which causes the annotation to be unreliable.

What does 'html lang mismatch' mean?

Each page in your hreflang set should have an html lang attribute that matches its declared hreflang code. A mismatch suggests a copy-paste error or templating issue. Google does not use html lang for language detection, but mismatches signal implementation problems.