Supported Resource File Formats for Translation with PTC
PTC (Private Translation Cloud) translates the resource files that store the text in your software - app labels, error messages, onboarding copy, and user content - while leaving keys, structure, and code untouched.
Pick a format below to jump to a working example of its source file, its translated form, and a link to the step-by-step guide for that format.
Gettext.pot · .po
JSON.json
YAML.yaml · .yml
Android Strings.xml
Apple Strings.strings
Apple Stringsdict.stringsdict
Apple String Catalogs.xcstrings
Apple Property List.plist
Java Properties.properties
CSV.csv
XLIFF.xliff
Gettext (.pot, .po)
Gettext splits translation across two files. The .pot template lists every translatable string in the source language, and each .po file pairs those strings with their translation for one target language.
Used for: WordPress themes and plugins, and Python internationalization.
Structure: every entry has a msgid (the original string) and a msgstr (its translation). PTC fills in each empty msgstr and never changes the msgid.
Source file
msgid "Hello, world!"
msgstr ""
Translated file
msgid "Hello, world!"
msgstr "¡Hola, mundo!"
How to translate PO and POT files
JSON (.json)
JSON stores translatable text as key-value pairs, where each key identifies a string and the value holds the text to translate. PTC translates the values and keeps every key intact.
Used for: web applications (React, Angular, Vue.js) and mobile apps (iOS, Android).
Source file
{
"welcome_message": "Welcome to our app!",
"error_message": "Something went wrong. Please try again."
}Translated file
{
"welcome_message": "¡Bienvenido a nuestra aplicación!",
"error_message": "Algo salió mal. Inténtalo de nuevo."
}JSON also stores related strings - such as a list of steps - in arrays. PTC translates each item and preserves the array order.
Source file
{
"steps": [
"Open the app.",
"Log in to your account.",
"Select your profile."
]
}Translated file
{
"steps": [
"Abre la aplicación.",
"Inicia sesión en tu cuenta.",
"Selecciona tu perfil."
]
}YAML (.yaml, .yml)
YAML holds translatable text in a clean, indented set of key-value pairs. Each key names a string and its value carries the text. PTC translates the values and keeps the indentation and keys exactly as they were.
Used for: Ruby on Rails apps, static site generators (Jekyll, Hugo), and CI/CD pipeline configuration.
Source file
welcome_message: "Welcome to our app!"
error_message: "Something went wrong. Please try again."Translated file
welcome_message: "¡Bienvenido a nuestra aplicación!"
error_message: "Algo salió mal. Inténtalo de nuevo."How to translate Ruby on Rails apps
Android Strings (.xml)
Android wraps each translatable string in a <string> tag identified by a unique name. PTC translates the text inside the tags and keeps every name unchanged.
Used for: Android mobile apps (UI strings and messages).
Source file
<resources>
<string name="welcome_message">Welcome to our app!</string>
<string name="error_message">Something went wrong. Please try again.</string>
</resources>Translated file
<resources>
<string name="welcome_message">¡Bienvenido a nuestra aplicación!</string>
<string name="error_message">Algo salió mal. Inténtalo de nuevo.</string>
</resources>Apple Strings (.strings)
An Apple .strings file is a simple key-value list where the key is the original text and the value holds the translation. Comments above an entry give translators context. Files use UTF-16 encoding by default and can be converted to UTF-8.
Used for: iOS and macOS applications (UI strings and system messages).
Source file
/* Welcome message shown on the home screen */
"welcome_message" = "Welcome to our app!";
/* Error message when something goes wrong */
"error_message" = "Something went wrong. Please try again.";
Translated file
/* Welcome message shown on the home screen */
"welcome_message" = "¡Bienvenido a nuestra aplicación!";
/* Error message when something goes wrong */
"error_message" = "Algo salió mal. Inténtalo de nuevo.";
Apple Stringsdict (.stringsdict)
A .stringsdict file handles plurals and other count-based wording that a flat .strings file cannot. It uses nested dictionaries to define a different string for each plural category, and PTC translates every plural form for the target language.
Used for: iOS and macOS apps that need plural forms, dynamic content, or gender-based wording.
Source file
<plist version="1.0">
<dict>
<key>apples_count</key>
<dict>
<key>NSStringLocalizedFormatKey</key>
<string>%#@apples@</string>
<key>apples</key>
<dict>
<key>NSStringFormatSpecTypeKey</key>
<string>NSStringPluralRuleType</string>
<key>NSStringFormatValueTypeKey</key>
<string>d</string>
<key>one</key>
<string>%d apple</string>
<key>other</key>
<string>%d apples</string>
</dict>
</dict>
</dict>
</plist>Translated file
<plist version="1.0">
<dict>
<key>apples_count</key>
<dict>
<key>NSStringLocalizedFormatKey</key>
<string>%#@apples@</string>
<key>apples</key>
<dict>
<key>NSStringFormatSpecTypeKey</key>
<string>NSStringPluralRuleType</string>
<key>NSStringFormatValueTypeKey</key>
<string>d</string>
<key>one</key>
<string>%d manzana</string>
<key>other</key>
<string>%d manzanas</string>
</dict>
</dict>
</dict>
</plist>Apple String Catalogs (.xcstrings)
String Catalogs are the modern Apple format that keeps every language in one JSON-based .xcstrings file. Each entry holds the source string plus a nested localization per language, and can carry developer notes, plural rules, and placeholders. PTC adds each target language as a new localization alongside the source.
Used for: any Apple platform app targeting iOS 15 / macOS 12 / tvOS 15 / watchOS 8 / visionOS 1 or later.
Source file
{
"sourceLanguage" : "en",
"strings" : {
"welcome_message" : {
"extractionState" : "extracted_with_value",
"localizations" : {
"en" : {
"stringUnit" : {
"state" : "translated",
"value" : "Welcome to our app!"
}
}
}
}
},
"version" : "1.0"
}Translated file
{
"sourceLanguage": "en",
"strings": {
"welcome_message": {
"extractionState": "extracted_with_value",
"localizations": {
"en": {
"stringUnit": {
"state": "translated",
"value": "Welcome to our app!"
}
},
"es": {
"stringUnit": {
"state": "translated",
"value": "¡Bienvenido a nuestra app!"
}
}
}
}
},
"version": "1.0"
}Apple Property List (.plist)
A .plist file stores simple key-value text in Apple's XML-based format. Unlike a Stringsdict, it carries plain strings with no plural logic, so it suits straightforward UI text and configuration values. PTC translates each value and keeps the keys.
Used for: iOS and macOS applications (UI text and configuration settings).
Source file
<plist version="1.0">
<dict>
<key>welcome_message</key>
<string>Welcome to our app!</string>
<key>error_message</key>
<string>Something went wrong. Please try again.</string>
</dict>
</plist>Translated file
<plist version="1.0">
<dict>
<key>welcome_message</key>
<string>¡Bienvenido a nuestra aplicación!</string>
<key>error_message</key>
<string>Algo salió mal. Inténtalo de nuevo.</string>
</dict>
</plist>Java Properties (.properties)
A Java .properties file lists one key=value pair per line, where the key identifies a string and the value holds the text. PTC translates the values and keeps the keys. Files use ISO-8859-1 by default and support UTF-8 for a wider character range.
Used for: Java web and desktop applications - UI elements, error messages, and system prompts.
Source file
welcome_message=Welcome to our app!
error_message=Something went wrong. Please try again.Translated file
welcome_message=¡Bienvenido a nuestra aplicación!
error_message=Algo salió mal. Inténtalo de nuevo.How to translate Java .properties files
CSV (.csv)
A CSV file holds one key-value pair per row: the first column is the key or original string, and the second column holds the translation. PTC translates the second column and keeps the keys and delimiters intact.
Used for: Magento and Adobe Commerce product descriptions and UI labels, and bulk import/export of localization data in e-commerce platforms.
Source file
"welcome_message","Welcome to our store!"
"error_message","Something went wrong. Please try again."
Translated file
"welcome_message","¡Bienvenido a nuestra tienda!"
"error_message","Algo salió mal. Inténtalo de nuevo."
XLIFF (.xliff)
XLIFF is a standard exchange format that pairs each source string with its translation inside a <trans-unit>. PTC fills in each empty <target> and leaves the <source> and unit identifiers unchanged.
Used for: software and website localization, translation management systems, and CMS or authoring tools.
Source file
<xliff version="1.2">
<file source-language="en">
<body>
<trans-unit id="1">
<source>Hello, world!</source>
<target></target>
</trans-unit>
</body>
</file>
</xliff>Translated file
<xliff version="1.2">
<file source-language="en" target-language="es">
<body>
<trans-unit id="1">
<source>Hello, world!</source>
<target>¡Hola, mundo!</target>
</trans-unit>
</body>
</file>
</xliff>Translate Your Resource Files with PTC
Once you start a free 30-day trial, translating your resource files with PTC is simple. Translate up to 20,000 words into 2 languages for free. When you’re ready for more, activate Pay-As-You-Go pricing for unlimited translations into unlimited languages - you only pay for what you translate.
You choose how to handle translations and provide context, and PTC delivers human-quality translations at machine speed and cost.
Learn more in our Getting Started Guide.