translations_cleaner

Dart package to search and delete unused translations from .arb files, for all languages, all in one go.

NOTE : This package has been developed keeping flutter_localizations package in mind, which uses .arb files for all translations.

Usage

# Add translations_cleaner as a dev dependency
dart pub add --dev translations_cleaner

dart run translations_cleaner <command> [arguments]
# OR
flutter pub run translations_cleaner <command> [arguments]

Commands Available

• clean-translations - Search all the translations listed in arb files and delete the unused translations
• list-unused-terms - Search all the translations listed in arb files and print/save a list of unused translations.
• sort-translations - Sorts all the translations in arb files alphabetically.

Options Available

Available only for list-unused-terms

• -a, --[no-]abort-on-unused - Abort execution if unused translations are found. This can be helpful in CI, if you don't want to proceed if a build should fail.

Available for clean-translations and list-unused-terms

• -h, --help - Print this usage information.
• -o, --output-path - Path for saving exported file, defaults to root path of the folder
• -e, --[no-]export - Save unused keys as a .txt file in the path provided
• -s, --include-subpackages - Include arb files from subpackages (directories with their own pubspec.yaml). By default, subpackages are excluded to avoid false positives in monorepo setups.

Why 🤔

Translations can be a very time consuming process when the app starts to scale and there are lots of translations. It is a good practice to clean out translations that are not being used. Checking for unused translations is tedious, hence this package.

How 🤖

• translations_cleaner looks for all the .arb files located in the directory, and fetches all the translations, from all the languages.
• Then it looks for all the .dart files.
• It parses Dart files with AST and detects key usage from localization-style member access and matching top-level functions.
• The translations not found in the dart files are removed from the corresponding .arb files, including any attributes as well

Detection: regex → AST

Unused keys used to be detected by scanning Dart files as raw text with word-boundary regex. That often marked keys as "used" when they only appeared in comments, string literals, or generated code (e.g. AppLocalizations getters). Detection is now AST-based: we parse each Dart file and only count a key as used when it appears as a member on a localization-like target (e.g. context.l10n.someKey, AppLocalizations.of(context).someKey) or as a top-level function call with the same name. That reduces false positives and aligns results with actual usage.

Performance

• Regex (old): Single pass over file contents with precompiled patterns; very fast but prone to false positives.
• AST (current): Each Dart file is parsed once; more work per file but only lib/**/*.dart is scanned. On large projects you may notice a few extra seconds; list-unused-terms prints timing so you can compare.

Limitations 😔

• This package currently works only for l10n achieved via flutter_localizations, which uses .arb files.
• There are other l10n packages which use .json and .yaml for saving translations. These are not supported currently

Bugs / issues

If you run into bugs or unexpected behavior, please open an issue: github.com/Chinmay-KB/translations_cleaner/issues