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A toolchain for working with localization files in a platform-agnostic way.


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localicious is a toolchain for working with localization files in a platform-agnostic way. With it, you can:

  • Maintain all your localized copy and accessibility key/value pairs in one file, grouped per component.
  • Verify the integrity of your base localization file against a schema
  • Generate locale files for both Android, iOS or JS from your base localization file

The goals of localicious are:

  • Copywriter-friendliness

    Likewise, it should be easy for copywriters to change and add copy. For each string copywriters should be able to easily get an overview of the translations provided for the various languages.

  • Developer-friendliness

    It should be easy for developers maintaining and developing features to work with the new system. They should be able to trust that the necessary copy will be there for any language. Moreover, the format in which the copy is delivered should be predictable to minimise dependencies between developers and copywriters in a fast-paced environment.

  • Robustness

    One cannot blindly import localization files into the app and expect everything to work. Therefore, localicious enables both validation and conversion. Together, these two operations can support a robust workflow that minimises the potential for mistakes.


localicious assumes the following workflow:

  1. You keep all your localizable strings in a YAML file that adheres to the structure defined by localicious.
  2. When committed to a source repository, the YAML file is guaranteed to have passed localicious verification.
  3. You point to the current working version of the YAML file in your iOS or Android project.
  4. Using localicious, you generate the localization files when desired.

Requirements and installation

localicious requires node 10.12.0 or later.

The Localicipe

The central concept of localicious is the so-called Localicipe. It is a YAML file that contains all localized copy and accessibility strings grouped by feature and screen. The strings in the Localicipe can be divided into different collections. Multiple collections can be combined when Converting the Localicipe into platform specific outputs.

Using collections it's easy to keep track of strings that are used on a single platform and strings that are shared across multiple platforms. For an existing iOS and Android app, it could be useful to create three different collections:

  • IOS(containing all iOS specific strings)
  • ANDROID(containing all Android specific strings)
  • SHARED(containing all strings that are shared between iOS and Android).

Each leaf node in a collection is either a COPY group or an ACCESSIBILITY group. The required structure of both groups is explained below:

          en: "Translation for English speakers"
          nl: "Vertaling voor Nederlandstaligen"
            en: "Accessibility for English speakers"
            nl: "Toegankelijkheid voor Nederlandstaligen"
            en: "Plural translation for English speakers"
            nl: "Meervoudige vertaling voor Nederlandstaligen"

Retrieving the Localicipe

If you are working with a team, you probably want to store your Localicipe in a Git repository and manage changes like you handle changes to your source code. Localicious supports that workflow. Simply create a repository that hosts your Localicipe. Then, in the root of the source repository of your Android or iOS project, you add the following LocaliciousConfig.yaml:

    url: ''
  - en
  - nl
  - IOS
  - IOS

To retrieve the latest version of the file in your repository, simply run localicious install. localicious also supports specifying a specific Git branch (by adding :branch).

Converting the Localicipe

Using the render command, a Localicipe can be converted into platform specific outputs. Here's an overview on how the command works:


localicious render <localicipe path> <output path>


--outputTypes/-ot (required)

  • The platform/language for which the output files will be generated (Localized.strings for iOS, strings.xml for Android, strings.json for JS).
  • Available options are: ios, android or js

--collections/-c (required)

  • The collections, defined in the Localicipe, that should be included into the output.

--languages/-l (required)

  • The languages that should be included into the output.

Consider the following Localicipe:

# Strings that are used in Android only
          en: 'Total price: %1{{s}}'  # This placeholder will expand to %1$@ on iOS and %1$s on Android
          nl: 'Totaal: %1{{s}}'
# Strings that are used in iOS only
          en: 'Stay up to date'
          nl: 'Blijf op de hoogte'
# Strings that are shared between Android and iOS
          en: "Help"
          nl: "Help"
            en: '%1{{d}} Pending order'
            nl: '%1{{d}} Lopende bestelling'
            en: '%1{{d}} Pending order'
            nl: '%1{{d}} Lopende bestelling'
            en: '%1{{d}} Pending Orders'
            nl: '%1{{d}} Lopende bestellingen'

By running the following localicious command:

localicious render ./copy.yaml ./output_path --outputTypes android --collections ANDROID,SHARED --languages en

We can generate a strings.xml file for Android with the English translations provided:

<?xml version="1.0" encoding="utf-8"?>
  <string name="Checkout.OrderOverview.Total.COPY">Total price: %1$s</string>
  <string name="Delivery.Widget.Title.COPY">Help</string>
  <plurals name="Delivery.Widget.SubTitle.COPY">
    <item quantity="zero">%1$d Pending order</item>
    <item quantity="one">%1$d Pending order</item>
    <item quantity="other">%1$d Pending Orders</item>

A similar file with the Dutch translations will be created as well if we request localicious to do so:

localicious render ./copy.yaml ./output_path --outputTypes android --collections ANDROID,SHARED --languages en,nl

By changing the destination output type, like so:

localicious render ./copy.yaml ./output_path --outputTypes ios --collections IOS,SHARED --languages en

the following Localizable.strings file will be generated for iOS:

"Settings.PushPermissionsRequest.Title.COPY" = "Stay up to date";
"Delivery.Widget.Title.COPY" = "Help";
"Delivery.Widget.SubTitle.COPY.ZERO" = "%1$d Pending order";
"Delivery.Widget.SubTitle.COPY.ONE" = "%1$d Pending order";
"Delivery.Widget.SubTitle.COPY.OTHER" = "%1$d Pending Orders";


Whenever we make changes to the Localicipe, it is important to verify that the format of the file is still correct. Using the validate command, a Localicipe can be validated.


localicious validate <localicipe path> <output path>


--collections/-c (required)

  • The collections, defined in the Localicipe, that should be validated.

--required-languages/-l (required)

  • The languages that are required in the provided Localicipe.


  • The languages that are optional in the provided Localicipe.

Imagine that we change the file in the previous example and add another entry for iOS:

        en: 'Stay up to date'

Using the validation feature, we can validate whether the structure of the file is still correct after the change:

localicious validate ./copy.yaml --collections IOS --required-languages en,nl

Since we forgot to add a Dutch localization for the Settings.PushPermissionsRequest.Subtitle.COPY key, this will fail:

❌ Your Localicipe contains some issues.

localicious also supports the concept of optional languages. If we were to run the validator as follows:

localicious validate ./copy.yaml --collections IOS --required-languages en --optional-languages nl

the above file would pass validation even without the Dutch translation missing for some entries.


Read all migration details in our Migration Guide.