The SEO Pack Add-on allow you to translate various SEO elements from every page:
- URL post/page/custom post type slug
- page title
- page description
- image alt tag
- Facebook and Twitter title and descriptions (these are usually added by Yoast SEO and appear when users share your content)
To translate the above, simply select them from the string list under Meta Information, enter their translation and click “Save translation”.
The addon also adds support for Yoast SEO Sitemaps so they correctly represent each individual translation.
The translation alternate links are implemented as specified in the Google Webmasters documentation.