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SEO fix guide

Language Declaration vs Detected Language

The declared HTML lang attribute does not match the detected language of the page content. This confuses assistive technologies and search engines.

Issue ID: INTL-LANG-MISMATCH-001
Severity: moderate
Impact: Med
Effort: S

Use this article when

  • You need deeper remediation guidance than the issue card can show.
  • You want CMS-specific steps before handing the fix to a developer.
  • You want a repeatable re-check path after shipping the change.
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What this issue is

The declared HTML lang attribute does not match the detected language of the page content. This confuses assistive technologies and search engines.

Why it matters

The declared HTML lang attribute does not match the detected language of the page content. This confuses assistive technologies and search engines. This affects how clearly search engines understand the page and how persuasive it looks in search results.

How we detect it

  • FreeSiteAudit flags this issue when the rule for INTL-LANG-MISMATCH-001 fails and the page evidence points to Head metadata.
  • You can usually confirm this by checking the page source or the relevant page settings inside your CMS.

Evidence examples

Check the affected page source, rendered output, or relevant CMS setting to confirm the missing or incorrect element.

How to fix it

  1. 1Set the lang attribute to match the actual language of the content
  2. 2If the page mixes languages, set lang on the primary language and use lang attributes on sections

How to re-check it

  • HTML lang attribute matches the dominant language of the page content

Related tools

This issue is best verified with the full FreeSiteAudit crawl rather than a single-point mini tool.