The hreflang attribute (also referred to as rel="alternate") tells Google which language you are using on a specific page, so the search engine can serve that result to users searching in that language.

The module

Considering the Magento multi store structure, this module will add the hreflang tag to the pages.

Code Sample

<link rel="alternate" href="http://example.com/en" hreflang="en-us" />
<link rel="alternate" href="http://example.com/pt" hreflang="pt-br" />

Installation details

Run composer require vandersonramos/magento2-hreflangtag
Run php bin/magento setup:upgrade
Run php bin/magento cache:clean

Uninstall

Run composer remove vandersonramos/magento2-hreflangtag