FormatJS translation with Crowdin

FormatJS's formatjs extract command outputs messages in a standard JSON shape ({ "id": { "defaultMessage", "description" } }) that Crowdin doesn't handle natively — so today you have to run formatjs extract --format crowdin to convert it first. This app reads the standard output directly, removing that extra step.

How It Works

Step 1: Upload extracted messages

Upload the JSON produced by formatjs extract. The app detects FormatJS-shaped catalogs (any .json containing defaultMessage) and leaves other JSON to Crowdin's native parser.

Step 2: Extract translatable content

Each message becomes a Crowdin string: defaultMessage is the source text and description is the translator context. ICU placeholders, plurals, and react-intl rich-text tags are kept verbatim.

Step 3: Translate in Crowdin

Translators work with the extracted strings, with the message id and description for context.

Step 4: Export translated files

Exports mirror the original structure, replacing only each defaultMessage with the translation while preserving description, key order, and any other fields — so the file is ready for formatjs compile.

Untranslated messages keep their source text.

The app also supports Crowdin bundles, generating a translated catalog for any target language.

File Format Details

Sample File

{
  "with.description": {
    "defaultMessage": "Save changes",
    "description": "primary action button"
  },
  "no.description": {
    "defaultMessage": "Cancel"
  },
  "empty.message": {
    "defaultMessage": "",
    "description": "intentionally empty, should be skipped"
  },
  "bare.string": "Logged compiled value still translatable",
  "object.description": {
    "defaultMessage": "Notifications",
    "description": { "context": "nav label", "component": "Sidebar" }
  }
}