Validate JSON locale files before they break your app
@json-translate/check is a free npm CLI for catching invalid JSON, missing keys, extra keys, and placeholder drift before translated files reach production.
npx @json-translate/check --source locales/en.json --target locales/fr.json --target locales/de.jsonInvalid JSON
Fail fast when a translated file cannot be parsed.
Key drift
Report missing and unexpected keys compared with the source locale.
Placeholder drift
Catch changed tokens such as {name}, {{count}}, ${value}, and %s.
How it fits a release workflow
Translate files
Use JSON Translate to generate draft locale JSON for new target languages.
Run the checker
Compare each translated file against the source locale locally or in CI.
Review issues
Fix missing keys and placeholders before they reach customers.
GitHub Actions example
Add the dedicated Action to a pull-request workflow and list each target locale in targets.
- name: Check translated JSON locales
uses: OlsOls2/json-translate-check-action@v1
with:
source: locales/en.json
targets: locales/fr.json,locales/de.json