lingolint

Catch translation bugs before your users do. ESLint for app translations.

npx lingolint scan ./locales --source en

Compares your locale JSON files and reports missing keys, obsolete keys, empty strings, placeholder mismatches ({amount}, {{amount}}, %s, …), unbalanced HTML tags, suspicious whitespace, untranslated strings, length outliers and duplicate translations. Exits 1 when errors are found, so the same command gates your CI.

Spanish (es) — 72/100

✖ ERROR  checkout.total
  Missing placeholder: {currency}
  Source:       "Total: {amount} {currency}"
  Translation:  "Total: {amount}"

• Works offline. No account, server or API key.
• Nested JSON, ICU, i18next, printf and template placeholder styles.
• --format json for integrations, --fail-on for CI thresholds.
• Optional AI review with your own key (--ai).

Full documentation, configuration reference and contribution guide: https://github.com/wpfsg/lingolint

Install

npm install -D lingolint

Node.js 20.19+.

Configure

lingolint.config.ts:

import { defineConfig } from 'lingolint';

export default defineConfig({
  sourceLocale: 'en',
  localesPath: './locales',
  failOn: 'error',
  rules: {
    length: ['warning', { maxRatio: 3 }],
    identicalToSource: ['warning', { ignore: ['Notely'] }],
  },
});

CI

- run: npx lingolint scan ./locales --source en --fail-on error

MIT licensed.