hreflang and SEO

hreflang links tell Google and other search engines that /about/ and /fr/about/ are the same page in two languages, so each searcher gets the right one.

• With a translation plugin: your translation plugin adds hreflang links. Language Switcher Pro adds none, so there are no duplicates.
• With built-in URLs: Language Switcher Pro adds them for every enabled language, plus an x-default link to your default language. Turn this off in Advanced → Search engines → Tell search engines about translations only if an SEO plugin already adds them.

hreflang links are not added on search results, 404 pages, paginated archives (page 2 and later), attachments, feeds and previews, because these are not real translations of each other. They are also not added when only one language is enabled.

Other SEO safeguards:

• Search engines, social previews and SEO tools are never redirected and never see banners, so every language can be crawled and indexed.
• Language links in the window and the grid are real links with hreflang and lang attributes, so crawlers can follow them.
• Redirects are sent as temporary (302) redirects with no-cache headers.