There is built in support for pseudolocalization <>. Pseudolocalization is a method for testing the internationalization aspects of your application by replacing your strings with altered versions and maintaining string readability. It also makes hard coded strings and improperly concatenated strings easy to spot so that they can be properly localized.

Example: Ţĥĩś ţēxţ ĩś ƥśēũďōĺōćàĺĩźēď


To setup pseudolocalization add pseudoLocale to your lingui configuration file:

   "lingui": {
      "locale": ["en", "pseudo-LOCALE"],
      "pseudoLocale": "pseudo-LOCALE"
      "fallbackLocales": {
         "pseudo-LOCALE": "en"

pseudoLocale option can be any string that is in locale

Examples: en-PL, pseudo-LOCALE, pseudolocalization or en-UK

Create pseudolocalization

PseudoLocale string have to be in locales config as well. Otherwise no folder and no pseudolocalization is going to be created. After running yarn extract verify that the folder has been created. The pseudolocalization is automatically created on yarn compile from messages in order specified in in this cli section. In case fallbackLocales has been used, the pseudolocalization is going to be created from translated fallbacklocale.

Switch browser into specified pseudoLocale

We can use browsers settings or extensions. Extensions allow to use any locale. Browsers are usually limited into valid language tags (BCP 47). In that case, the locale for pseudolocalization has to be standard locale, which is not used in your application for example zu_ZA Zulu - SOUTH AFRICA

Chrome: a) With extension (valid locale) - b) Without extension (valid locale) - chrome://settings/?search=languages

Firefox: a) With extension (any string) - b) Without extension (valid locale) - about:preferences#general > Language