i18n library for node and the browser


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mondo is a i18n library for node and the browser. It features date- and number formatting, translations with string interpolation and pluralization.

see github issues for open task prior version 1.0.0

mondo uses several other libraries under the hood:

  • globalize - This library does the heavy lifting. globalize provides all the locale information for formatting and parsing.

  • handlebars - mondo uses handlebar templates for string interpolation

  • CLDR.js - provides the pluralization rules. For futher information please refer to the CLDR page on

  • underscorejs - No need to introduce this famous citizen of jsworld


Mondo.format(value, format) alias: Mondo.f(value, format)

Formats the given value according to the format. Please see ( for details and formatting patterns. alias: Mondo.d(date)

Shortcut for format(date, 'd') uses the short date pattern. e.g. "dd.MM.yyyy" for de-CH locale

Mondo.time(date) alias: `Mondo.t(date)

Shortcut for format(date, 't') uses the short time pattern. e.g. "" for de-CH locale

Add translation messages to the given locale (culture in globalize speak) definition.

Mondo.addTranslations('en-US', { title: "Super awesome webapp" })

To access the title message use:


It's possible to define nested message for a cleaner message file if lots of messages are used.

Mondo.addTranslations('en-US', { loginForm: { labels: { username: "Username", password: "Password"}} })

To access nested messages concatenate the single message keys by '.'


Mondo.addTranslations('en-US', { messageCount: { one: "message" other: "messages" })

Be aware languages have different rules for pluralization. English as in the above example knows only two different forms. Please refer to [] or CLDR.js for further information. Allowed pluralization labels are: zero, one, two, few, many, other.

In addition to the key for the message you need to pass in the pluralization option. Don't include the pluralization label into the message key.

Mondo.localize('messageCount', { pluralize: 1 }) or localize('messageCount', { pluralize: 2 });

Allowed values for the pluralize option are:

  • Numbers
  • Every object containing a length attribute or function, like Arrays.
  • Every object containing a size attribute or function.
  • Simple objects. The number of attributes is used.

Shortcut if no other options need to be passed:

Mondo.localize('messageCount', 1)

Handlebars templates can be used to define interpolatable messages.

Mondo.addTranslations('de-DE', { loggedInUser: "Sie sind eingeloggt als {{loginName}}"});

Using interpolation:

Mondo.localize("loggedInUser", { loginName: "lchngr" })

All options passed to the localize function passed to the handlebars template except the pluralize option.


  • {{d date}} Formats the given date as a localized date
  • {{t time}} Formats the given date as a localized time
  • {{p number}} Formats the given number as percentage. e.g. n=1.23 --> '123%'
  • {{c amount}} Formats the given amount as localized currency a=123 --> 'Fr. 123'
  • {{f value format}} Formats the given value into the given format string. For details see: globalize