home_url() vs site_url()

When working with domain-mapped sites on WordPress.com, home_url() and site_url() will return different values.

• home_url() returns the primary mapped domain (e.g. vippuppies.com)
• site_url() returns the *.wordpress.com URL (e.g. vippuppies.wordpress.com)

A few notes:

• home_url() will only return the mapped domain on or after the init has fired. Calling it before then will return the .wordpress.com domain.
• If you accidentally use site_url() in your templates, theme-side links will still redirect correctly to the home_url() equivalent.
• home_url() is the preferred method, as it avoids the above redirect.