---
title: Documentation
url: "https://b13.com/products/hreflang-multisite-module-for-typo3/documentation"
date: 2026-09-11
modified: 2026-09-30
lastUpdated: 2026-09-30
---

# Documentation

![Graphic featuring a stylized link icon surrounded by overlapping shapes, set against a blue background with a gradient.](https://b13.com/fileadmin/_processed_/7/8/csm_sharing-ext-hreflang_multisite-S_a5297c2e15.webp)

 Documentation
===============

 TYPO3 Extension “Hreflang Multisite”
 Version 2.3.1 (2026-09-30)

  TYPO3 builds valid hreflang tags on its own, but only for translations inside **one** page tree. Run Europe, North America, and Asia as three separate root pages and you have three websites that never reference each other—each one tells search engines it is the only version that exists.

This extension adds a field that links pages across root pages into a single **page set**. Every page in the set carries the hreflang tags of all the others, including their translations.

   Compatibility
---------------

TYPO3 v13.4 LTS and v14.3 LTS, PHP 8.2 or higher. The system extensions `info` and `seo` are pulled in automatically as dependencies.

Release notes live in the [changelog](https://b13.com/products/hreflang-multisite-module-for-typo3/documentation/changelog).

   Contents
----------

| Chapter | What It Covers |
|---|---|
| [Installation](https://b13.com/products/hreflang-multisite-module-for-typo3/documentation/installation) | Requirements, site set versus PageTsConfig, going live |
| [Page Sets](https://b13.com/products/hreflang-multisite-module-for-typo3/documentation/page-sets) | What a set is, when this extension applies, `x-default` |
| [Editing](https://b13.com/products/hreflang-multisite-module-for-typo3/documentation/editing) | Page properties, overview module, the configuration check |
| [Configuration](https://b13.com/products/hreflang-multisite-module-for-typo3/documentation/configuration) | Every PageTsConfig option and its default |
| [Events](https://b13.com/products/hreflang-multisite-module-for-typo3/documentation/events) | Changing the tags before they are rendered |

   Where to Start
----------------

**Not sure this is the right extension?** Read [When This Applies](https://b13.com/products/hreflang-multisite-module-for-typo3/documentation/page-sets#c12893) first. If your languages all live in one page tree, TYPO3 already does this and you do not need us.

**Setting it up?** [Installation](https://b13.com/products/hreflang-multisite-module-for-typo3/documentation/installation), then [Configuration](https://b13.com/products/hreflang-multisite-module-for-typo3/documentation/configuration).

**Editors cannot see the field?** It is hidden when the root page belongs to no `rootpage-sets` group, or when the page’s doktype is excluded. See [Configuration](https://b13.com/products/hreflang-multisite-module-for-typo3/documentation/configuration#c12917).

**Tags look wrong in the frontend?** Turn on the [language configuration check](https://b13.com/products/hreflang-multisite-module-for-typo3/documentation/editing#c12908)—it is off by default and reports duplicate hreflang codes across the root page group. Mind that it checks the configuration, not the set.

 Documentation