Migration to i18next-vue v3.x

If you used version 1.x/v2.x before, there are some breaking changes in version 3.

If you upgrade from version 1.x, setup of plugins has changed in Vue 3. Apart from the Vue 3 migration itself, the changes in i18next-vue should be the same as coming from 2.x.

There are additional instructions for upgrading from version 3 to version 4.

Breaking changes

• requires i18next >=23
  • Consult the i18next Migration Guide for updating.
• the 3.x package is ESM-only
  • Relevant only for CommonJS users, i. e. when using require() imports
• deprecated support for i18nOptions (Options API) removed in 4.0
  • You can use useTranslation() with its new parameters for most of these use-cases instead.
  • Legacy support for i18nOptions needs to be enabled explicitly via the legacyI18nOptionsSupport: true plugin option
  • This allows component-by-component migration to useTranslation() using the 3.x version. Support for i18nOptions is removed in 4.0.
• removed support for <i18n> blocks in SFCs and messages in i18nOptions
  • i.e. no more per-component translations
  • There is no replacement for this, as this seems to be a rarely used feature. If you do use this a lot, please open a feature request.

New/changed functionality

• new useTranslation() parameters to specify a fixed language, namespace(s) and a keyprefix (all optional)
• $t/t functions will return an empty string while i18next is loading
  • v2 returned the untranslated translation key, which is usually uglier
• support for TypeScript auto-completion of translation keys
  • via i18next's support for this
  • Your mileage may vary (dev performance, ...). If it works for you, it can be quite useful.