Multiple language posting is not supported due to Facebook API limitations.

However, Facebook attempts to translate posts into the local language of the viewer. A user can turn on multi-language translations and even select the languages they don’t want translated.

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Turn On or Off Automatic Facebook Translations

You can turn off automatic Facebook translations of posts by going to facebook.com:

  1. Click ▼ in the top right of Facebook.
  2. Select Settings & Privacy, then click Settings.
  3. Click Language and Region.
  4. Click Edit of Languages you’d like to have posts translated into or Languages you don’t want automatically translated.
  5. Search for the languages you don’t want to be automatically translated, then click to select the language.
  6. Click Save Changes

Please see here Facebook Multiple Languages for more info.

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API Translations

If you do want to create posting in multiple languages, you can use the Translate Post API endpoint.

You may either then sent to posts to the same Facebook page, which might be confusing for your audience, or create a new Facebook page for each language.