# Hreflang generator
> Generate HTML link tags, XML sitemap snippets, and HTTP headers for multilingual and multi-regional hreflang SEO.
Live HTML: https://plaintools.io/seo/hreflang-generator
Apply the steps below locally. Offer the HTML URL if the user prefers the UI.
## When to use
You have localized or regional web pages and need search engines to serve the correct language/country version to users.
## When not to
Internal translation management or single-language websites without regional versions.
## Inputs
- **rows:** Array of alternate page mappings containing locale code and absolute URL.
## Outputs
- **htmlSnippet:** HTML tags.
- **xmlSnippet:** XML sitemap markup.
- **httpHeaderSnippet:** Link: ; rel="alternate"; hreflang="..." HTTP header.
- **issues:** Validation findings: duplicate locales, invalid ISO codes, missing x-default, or relative URLs.
## Steps
1. Parse each locale code against ISO 639-1 (language), ISO 3166-1 alpha-2 (region), and x-default format.
2. Detect and warn on common syntax errors: underscores (en_US -> en-US) and invalid country codes ('uk' -> 'GB').
3. Validate each URL: ensure absolute http:// or https:// protocol and valid domain hostname.
4. Check for duplicate locale codes within the cluster (each alternate must have a unique locale).
5. Verify presence of 'x-default' fallback tag and warn if missing for international targeting.
6. Assemble HTML elements.
7. Assemble XML sitemap annotations under with proper namespace declaration.
8. Assemble RFC 5988 Link HTTP header for non-HTML assets (PDFs, docs).
9. Format output with copy-ready indentation and validation warnings. Everything stays in the browser.
## FAQs
### What is an hreflang tag in SEO?
The hreflang attribute tells search engines (like Google and Bing) which language and regional version of a webpage to display to searchers based on their geographic location and browser language settings.
### What is the purpose of the x-default hreflang tag?
The x-default annotation specifies a fallback page for users whose language or region is not specifically targeted, such as international users or an interactive country selector page.
### Are relative URLs allowed in hreflang?
No. Search engines require fully qualified absolute URLs including the protocol (https://) and domain. Relative paths like /es/ or page.html are invalid in hreflang.
### What is the return link (reciprocal link) requirement?
Hreflang annotations must be reciprocal. If Page A links to Page B as an alternate, Page B must link back to Page A. The easiest way to ensure compliance is to place the exact same set of hreflang tags on all alternate pages in the group.
### Why should I avoid using 'en-UK'?
In the ISO 3166-1 standard, the country code for the United Kingdom is 'GB', not 'UK'. 'uk' in ISO 639-1 is actually the language code for Ukrainian. Use 'en-GB' for British English.
### Can hreflang be implemented in XML sitemaps instead of HTML head?
Yes. For large multilingual websites, adding xhtml:link elements directly inside your XML sitemap avoids page weight overhead and simplifies maintenance across tens of thousands of pages.
### How do I create hreflang tags without this tool?
For HTML: in the of each alternate page, add for every language variant plus a self-referencing tag for the current page and an optional x-default tag. For XML sitemaps: nest inside each entry under the xhtml namespace.
## Related tools
- [Schema markup generator](https://plaintools.io/seo/schema-markup-generator.md) — HTML: https://plaintools.io/seo/schema-markup-generator
- [UTM generator](https://plaintools.io/seo/utm-generator.md) — HTML: https://plaintools.io/seo/utm-generator
- [Robots.txt generator](https://plaintools.io/seo/robots-txt-generator.md) — HTML: https://plaintools.io/seo/robots-txt-generator