This extension is part of the TYPO3 Core, but not installed by default.

Installation with Composer

Check whether you are already using the extension with:

composer show | grep linkvalidator

This should either give you no result or something similar to:

typo3/cms-linkvalidator       v12.4.11

If it is not installed yet, use the composer require command to install the extension:

composer require typo3/cms-linkvalidator

The given version depends on the version of the TYPO3 Core you are using.

Installation without Composer

In an installation without Composer, the extension is already shipped but might not be activated yet. Activate it as follows:

  1. In the backend, navigate to the Admin Tools > Extensions module.
  2. Click the Activate icon for the LinkValidator extension.
Extension manager showing LinkValidator extension

Extension manager showing LinkValidator extension

Next step

LinkValidator uses the HTTP request library shipped with TYPO3. Please have a look in the Global Configuration, particularly at the HTTP settings.

There, you may define a default timeout. Generally, it is recommended to always specify timeouts when working with the LinkValidator.