The LinkValidator is a tool for checking link in user input. It is part of the
If you are using Composer, you can install it like any other (Core) extension
requiring the package
composer require typo3/cms-linkvalidator
If you want to use the LinkValidator in the Scheduler, the system extension
scheduler also needs to be installed:
composer require typo3/cms-scheduler
If you are not using Composer, you may have to activate the LinkValidator in the Extension Manager.
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.