BartyCrouch incrementally updates your Strings files from your Code and from Interface Builder files. "Incrementally" means that BartyCrouch will by default keep both your already translated values and even your altered comments. Additionally you can also use BartyCrouch for machine translating from one language to 60+ other languages. Using BartyCrouch is as easy as running a few simple commands from the command line what can even be automated using a build script within your project.

Checkout this blog post to learn how you can effectively use BartyCrouch in your projects.


  • Xcode 13.0+ & Swift 5.5+
  • Xcode Command Line Tools (see here for installation instructions)

Getting Started


Via Homebrew

To install Bartycrouch the first time, simply run the command:

brew install bartycrouch

To update to the newest version of BartyCrouch when you have an old version already installed run:

brew upgrade bartycrouch
Via Mint

To install or update to the latest version of BartyCrouch simply run this command:

mint install Flinesoft/BartyCrouch


To configure BartyCrouch for your project, first create a configuration file within your projects root directory. BartyCrouch can do this for you:

bartycrouch init

Now you should have a file named .bartycrouch.toml with the following contents:

tasks = ["interfaces", "code", "transform", "normalize"]

paths = ["."]
defaultToBase = false
ignoreEmptyStrings = false
unstripped = false

codePaths = ["."]
localizablePaths = ["."]
defaultToKeys = false
additive = true
unstripped = false

codePaths = ["."]
localizablePaths = ["."]
transformer = "foundation"
supportedLanguageEnumPath = "."
typeName = "BartyCrouch"
translateMethodName = "translate"

paths = ["."]
sourceLocale = "en"
harmonizeWithSource = true
sortByKeys = true

paths = ["."]
duplicateKeys = true
emptyValues = true

This is the default configuration of BartyCrouch and should work for most projects as is. In order to use BartyCrouch to its extent, it is recommended though to consider making the following changes:

  1. To speed it up significantly, provide more specific paths for any key containing path if possible (especially in the update.transform section, e.g. ["App/Sources"] for codePaths or ["App/Supporting Files"] for supportedLanguageEnumPaths).
  2. Remove the code task if your project is Swift-only and you use the new transform update task.
  3. If you are using SwiftGen with the structured-swift4 template, you will probably want to use the transform task and change its transformer option to swiftgenStructured.
  4. If you decided to use the transform task, create a new file in your project (e.g. under SupportingFiles) named BartyCrouch.swift and copy the following code:
//  This file is required in order for the `transform` task of the translation helper tool BartyCrouch to work.
//  See here for more details:

import Foundation

enum BartyCrouch {
    enum SupportedLanguage: String {
        // TODO: remove unsupported languages from the following cases list & add any missing languages
        case arabic = "ar"
        case chineseSimplified = "zh-Hans"
        case chineseTraditional = "zh-Hant"
        case english = "en"
        case french = "fr"
        case german = "de"
        case hindi = "hi"
        case italian = "it"
        case japanese = "ja"
        case korean = "ko"
        case malay = "ms"
        case portuguese = "pt-BR"
        case russian = "ru"
        case spanish = "es"
        case turkish = "tr"

    static func translate(key: String, translations: [SupportedLanguage: String], comment: String? = nil) -> String {
        let typeName = String(describing: BartyCrouch.self)
        let methodName = #function

            "Warning: [BartyCrouch]",
            "Untransformed \(typeName).\(methodName) method call found with key '\(key)' and base translations '\(translations)'.",
            "Please ensure that BartyCrouch is installed and configured correctly."

        // fall back in case something goes wrong with BartyCrouch transformation
  1. If you don't develop in English as the first localized language, you should update the sourceLocale of the normalize task.
  2. If you want to use the machine translation feature of BartyCrouch, add translate to the tasks list at the top and copy the following section into the configuration file with secret replaced by your Microsoft Translator Text API Subscription Key:
paths = "."
secret = "<#Subscription Key#>"
sourceLocale = "en"


Before using BartyCrouch please make sure you have committed your code. Also, we highly recommend using the build script method described below.

bartycrouch accepts one of the following sub commands:

  • update: Updates your .strings file contents according to your configuration.
  • lint: Checks your .strings file contents for empty values & duplicate keys.

Also the following command line options can be provided:

  • -v, --verbose: Prints more detailed information about the executed command.
  • -x, --xcode-output: Prints warnings & errors in Xcode compatible format.
  • -w, --fail-on-warnings: Returns a failed status code if any warning is encountered.
  • -p, --path: Specifies a different path than current to run BartyCrouch from there.

update subcommand

The update subcommand can be run with one or multiple of the following tasks:

  • interfaces: Updates .strings files of Storyboards & XIBs.
  • code: Updates Localizable.strings file from NSLocalizedString entries in code.
  • transform: A mode where BartyCrouch replaces a specific method call to provide translations in multiple languages in a single line. Only supports Swift files.
  • translate: Updates missing translations in other languages than the source language.
  • normalize: Sorts & cleans up .strings files.

In order to configure which tasks are executed, edit this section in the config file:

tasks = ["interfaces", "code", "transform", "normalize"]
Options for interfaces
  • paths: The directory / directories to search for Storyboards & XIB files.
  • defaultToBase: Add Base translation as value to new keys.
  • ignoreEmptyStrings: Doesn't add views with empty values.
  • unstripped: Keeps whitespaces at beginning & end of Strings files.
Options for code
  • codePaths: The directory / directories to search for Swift code files.
  • localizablePaths: The enclosing path(s) containing the localized Localizable.strings files.
  • defaultToKeys: Add new keys both as key and value.
  • additive: Prevents cleaning up keys not found in code.
  • customFunction: Use alternative name to NSLocalizedString.
  • customLocalizableName: Use alternative name for Localizable.strings.
  • unstripped: Keeps whitespaces at beginning & end of Strings files.
  • plistArguments: Use a plist file to store all the code files for the ExtractLocStrings tool. (Recommended for large projects.)
Options for transform
  • codePaths: The directory / directories to search for Swift code files.
  • localizablePaths: The enclosing path(s) containing the localized Localizable.strings files.
  • transformer: Specifies the replacement code. Use foundation for NSLocalizedString or swiftgenStructured for L10n entries.
  • supportedLanguageEnumPath: The enclosing path containing the SupportedLanguage enum.
  • typeName: The name of the type enclosing the SupportedLanguage enum and translate method.
  • translateMethodName: The name of the translate method to be replaced.
  • customLocalizableName: Use alternative name for Localizable.strings.
Options for translate
Options for normalize
  • paths: The directory / directories to search for Strings files.
  • sourceLocale: The source language to harmonize keys of other languages with.
  • harmonizeWithSource: Synchronizes keys with source language.
  • sortByKeys: Alphabetically sorts translations by their keys.

lint subcommand

The lint subcommand was designed to analyze a project for typical translation issues. The current checks include:

  • duplicateKeys: Finds duplicate keys within the same file.
  • emptyValues: Finds empty values for any language.

Note that the lint command can be used both on CI and within Xcode via the build script method:

  • In Xcode the -x or --xcode-output command line argument should be used to get warnings which point you directly to the found issue.
  • When running on the CI you should specify the -w or --fail-on-warnings argument to make sure BartyCrouch fails if any warnings are encountered.

Localization Workflow via transform

When the transform update task is configured (see recommended step 4 in the Configuration section above) and you are using the build script method, you can use the following simplified process for writing localized code during development:

  1. Instead of NSLocalizedString calls you can use BartyCrouch.translate and specify a key, translations (if any) and optionally a comment. For example:
self.title = BartyCrouch.translate(key: "onboarding.first-page.header-title",  translations: [.english: "Welcome!"])
  1. Once you build your app, BartyCrouch will automatically add the new translation key to all your Localizable.strings files and add the provided translations as values for the provided languages.
  2. Additionally, during the same build BartyCrouch will automatically replace the above call to BartyCrouch.translate with the proper translation call, depending on your transformer option setting.

The resulting code depends on your transformer option setting:

When set to foundation, the above code will transform to:

self.title = NSLocalizedString("onboarding.first-page.header-title", comment: "")

When set to swiftgenStructured it will transform to:

self.title = L10n.Onboarding.FirstPage.headerTitle

Advantages of transform over the code task:

  • You can provide translations for keys without switching to the Strings files.
  • In case you use SwiftGen, you don't need to replace calls to NSLocalizedString with L10n calls manually after running BartyCrouch.
  • Can be combined with the machine translation feature to provide a source language translation in code and let BartyCrouch translate it to all supported languages in a single line & without ever leaving the code.

Disadvantages of transform over the code task:

  • Only works for Swift Code. No support for Objective-C. (You can use both methods simultaneously though.)
  • Xcode will mark the freshly transformed code as errors (but build will succeed anyways) until next build.
  • Not as fast as code since SwiftSyntax currently isn't particularly fast. (But this should improve over time!)

NOTE: As of version 4.x of BartyCrouch formatted localized Strings are not supported by this automatic feature.

Build Script

In order to truly profit from BartyCrouch's ability to update & lint your .strings files you can make it a natural part of your development workflow within Xcode. In order to do this select your target, choose the Build Phases tab and click the + button on the top left corner of that pane. Select New Run Script Phase and copy the following into the text box below the Shell: /bin/sh of your new run script phase:

if which bartycrouch > /dev/null; then
    bartycrouch update -x
    bartycrouch lint -x
    echo "warning: BartyCrouch not installed, download it from"

Next, make sure the BartyCrouch script runs before the steps Compiling Sources (and SwiftGen if used) by moving it per drag & drop, for example right after Target Dependencies.

Now BartyCrouch will be run on each build and you won't need to call it manually ever (again). Additionally, all your co-workers who don't have BartyCrouch installed will see a warning with a hint on how to install it.

Note: Please make sure you commit your code using source control regularly when using the build script method.

Exclude specific Views / NSLocalizedStrings from Localization

Sometimes you may want to ignore some specific views containing localizable texts e.g. because their values are going to be set programmatically.

For these cases you can simply include #bartycrouch-ignore! or the shorthand #bc-ignore! into your value within your base localized Storyboard/XIB file. Alternatively you can add #bc-ignore! into the field "Comment For Localizer" box in the utilities pane.

This will tell BartyCrouch to ignore this specific view when updating your .strings files.

Here's an example of how a base localized view in a XIB file with partly ignored strings might look like:

Here's an example with the alternative comment variant:

You can also use #bc-ignore! in your NSLocalizedString macros comment part to ignore them so they are not added to your Localizable.strings. This might be helpful when you are using a .stringsdict file to handle pluralization (see docs).

For example you can do something like this:

func updateTimeLabel(minutes: Int) {
  String.localizedStringWithFormat(NSLocalizedString("%d minute(s) ago", comment: "pluralized and localized minutes #bc-ignore!"), minutes)

The %d minute(s) ago key will be taken from Localizable.stringsdict file, not from Localizable.strings, that's why it should be ignored by BartyCrouch.

Things to Know:

  • Files named or files in folders named ".git", "carthage", "pods", "build",
    ".build" and "docs" (case insensitive) will always be ignored.


BartyCrouch was brought to you by Cihat Gündüz in his free time. If you want to thank me and support the development of this project, please make a small donation on PayPal. In case you also like my other open source contributions and articles, please consider motivating me by becoming a sponsor on GitHub or a patron on Patreon.

Thank you very much for any donation, it really helps out a lot! ?

Migration Guides

See the file


Contributions are welcome. Feel free to open an issue on GitHub with your ideas or implement an idea yourself and post a pull request. If you want to contribute code, please try to follow the same syntax and semantic in your commit messages (see rationale here). Also, please make sure to add an entry to the file which explains your change.

After Release Checklist:

  1. Run make portable_zip to generate .build/release/
  2. Create new release with text from new section & attach as binary
  3. Run pod trunk push to make a new release known to CocoaPods
  4. Update tag and revision in Formula/bartycrouch.rb, commit & push change
  5. Run brew bump-formula-pr bartycrouch --tag=<tag> --revision=<revision>


This library is released under the MIT License. See LICENSE for details.