converts gettext .mo or .po to 18next json format and vice versa
Latest commit c8f5f99 Jul 12, 2016 @perrin4869 perrin4869 v3.0.3


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Project goal is to convert files from gettext to i18next json format and vice versa.


  1. first install node.js from
  2. npm install i18next-conv -g

For i18next < 2.0.0 use i18next-conv@1.11.0, for i18next < 3.0.0 use i18next-conv@2.6.1


convert .mo or .po to i18next json

in your console type:

for help:

i18next-conv -h

to convert a .mo or .po file to i8next json:

i18next-conv -l [domain] -s [sourcePath] -t [targetPath]

eg.: i18next-conv -l en -s ./locales/en.po -t ./locales/en/translation.json

if no target (-t) is specified file will be stored to [sourceDir]/[domain]/translation.json.

to convert i18next json to a .mo or .po file:

i18next-conv -l [domain] -s [sourcePath] -t [targetPath]

eg.: i18next-conv -l en -s ./locales/en.translation.json -t ./locales/en/ (or .po)

if no target (-t) is specified file will be stored to [sourceDir]/[domain]/translation.po.

for utf8-encoded po-files add these lines to your po file:

"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"

It is necessary if you get corrupted output from the command above.

to filter incoming po-file translations, pass the path to a module that exports a filter function:

i18next-conv -l [domain] -s [sourcePath] -t [targetPath] -f [filterPath]

eg.: i18next-conv -l en -s ./locales/en.po -t ./locales/en/translation.json -f ./filter.js

The filter module should export a single function that accepts the gettext object, the domain and a callback as its arguments. The function can then add/edit/delete translations, invoking the callback with an error object and the translation table.


module.exports = function(gt, domain, callback) {
  var err;

  // Delete all keys without comments
  gt.listKeys(domain).forEach(key => {
    var comment = gt.getComment(domain, "", key);
    if (!comment) {
      gt.deleteTranslation(domain, "", key);

  callback(err, gt._domains[gt._textdomain]._translationTable);


.option('-b, --base [path]', 'Sepcify path for the base language file. only take effect with -K option', '')
.option('-f, --filter [path]', 'Specify path to gettext filter')
.option('-l, --language [domain]', 'Specify the language code, eg. \'en\'')
.option('-p, --pot', 'Generate POT file.')
.option('-s, --source [path]', 'Specify path to read from')
.option('-t, --target [path]', 'Specify path to write to', '')
.option('-K, --keyasareference', 'Deal with the reference comment as a key', false)
.option('-ks, --keyseparator [path]', 'Specify keyseparator you want to use, defaults to ##', '##')
.option('-P, --plurals [path]', 'Specify path to plural forms definitions')
.option('--quiet', 'Silence output', false)
.option('--skipUntranslated', 'Skip untranslated keys when converting into json', false)
.option('--splitNewLine', 'Silence output', false)
.option('--ctxSeparator [sep]', 'Specify the context separator', '_')
.option('--ignorePlurals', 'Do not process the plurals')


This module exposes a few functions to convert json to gettext and gettext to json. It accepts the same options as the cli.

const path = require('path');
const { readFileSync, writeFileSync } = require('fs');
const {

const source = path.join(__dirname, '../locales/ua-UK/translation.json');
const options = {/* you options here */}

function save(target) {
  return result => {
    writeFileSync(result, target);

i18nextToPo('ua-UK', readFileSync(source), options).then(save('../locales/ua-UK/translation.po'));
i18nextToPot('ua-UK', readFileSync(source), options).then(save('../locales/ua-UK/translation.pot'));
i18nextToMo('ua-UK', readFileSync(source), options).then(save('../locales/ua-UK/'));

gettextToI18next('ua-UK', readFileSync('../locales/ua-UK/translation.po'), options)

All credits go to


See the LICENSE file for license rights and limitations.