Convert Multi-language JSON to ARB online
Upload a Multi-language JSON file and download it as Flutter ARB. Translation keys, plurals and placeholders are preserved. Free, no account needed.
Pick the source format or let the converter detect it from the file.
Choose the format you want to download.
Application Resource Bundle files are JSON documents with ICU message syntax and optional @metadata entries. Flutter's gen_l10n tool turns them into typed Dart localization classes.
Need it the other way round? Convert ARB to Multi-language JSON.
From: Multi-language JSON
A single JSON file where every translation key holds an object with one entry per language. Handy for small projects, static sites and CDN delivery because all languages travel together.
Used by: custom i18n setups, static site generators, CDN delivery. All languages in one file. Read the Multi-language JSON format guide.
{
"en_US": {
"hello.world": "Hello World!",
"my_address": "My address"
},
"pl_PL": {
"hello.world": "Witaj Świecie!",
"my_address": "Mój adres"
}
}To: Flutter ARB
Application Resource Bundle files are JSON documents with ICU message syntax and optional @metadata entries. Flutter's gen_l10n tool turns them into typed Dart localization classes.
Used by: Flutter, Dart intl, gen_l10n. One language per file. Read the ARB format guide.
{
"@@locale": "en",
"hello.world": "Hello World!",
"@hello.world": {
"description": "Hello world message"
}
"my_address": "Address",
}How to convert Multi-language JSON to ARB
- Drop your .json file into the converter above, or paste its content.
- Click Convert. You get one .arb file per language.
- Preview the result, copy it or download the files.
What changes between Multi-language JSON and ARB
- Multi-language JSON holds every language in one file, so the converter writes one ARB file per language found in the source.
Convert and translate in one place
If you need the ARB file in more languages, the fastest route is a free SimpleLocalize project: import the Multi-language JSON file, add languages, run auto-translation with DeepL, Google Translate, OpenAI, Claude or Gemini, and download the result as ARB. The CLI does the same from CI with upload and download commands, so the conversion becomes part of your build. See also translating Multi-language JSON files.
Frequently asked questions
Is the converter free?
Yes. There is no signup and no limit on the number of conversions beyond a few requests per second.
Are my files stored?
No. The file is parsed in memory, converted and returned in the same request. Nothing is written to disk or a database.
What about plurals and placeholders?
Plural forms are normalized to ICU message syntax and written back in the native form of ARB. Placeholders are kept, and Apple and Android specific syntax is translated between platforms. Read more in the pluralization guide.
Convert Multi-language JSON to other formats
Convert other formats to ARB
Translate your ARB files
- Import Multi-language JSON or ARB files into a free project
- Auto-translate with DeepL, Google, OpenAI, Claude or Gemini
- Download in any of the supported formats or publish to the CDN