If the small-icu option is used, one can still provide additional locale data at runtime so that the JS methods would work for all ICU locales. Assuming the data file is stored at /some/directory, it can be made available to ICU through either:

    • The [NODE_ICU_DATA][] environment variable:

      1. env NODE_ICU_DATA=/some/directory node

    • The [--icu-data-dir][] CLI parameter:

      1. node --icu-data-dir=/some/directory

    (If both are specified, the --icu-data-dir CLI parameter takes precedence.)

    ICU is able to automatically find and load a variety of data formats, but the data must be appropriate for the ICU version, and the file correctly named. The most common name for the data file is icudt6X[bl].dat, where 6X denotes the intended ICU version, and b or l indicates the system’s endianness. Check [“ICU Data”][] article in the ICU User Guide for other supported formats and more details on ICU data in general.

    The [full-icu][] npm module can greatly simplify ICU data installation by detecting the ICU version of the running node executable and downloading the appropriate data file. After installing the module through npm i full-icu, the data file will be available at ./node_modules/full-icu. This path can be then passed either to NODE_ICU_DATA or --icu-data-dir as shown above to enable full Intl support.