Software Localization Process and Best Practices: The Complete Guide 

Learn software localization best practices for structuring code, preparing content, and designing interfaces for different text lengths.

The work you do before software localization determines the quality of your final product. Hard-coded strings, concatenated dynamic text, and fixed-width UI elements often lead to broken translations or UI bugs later on.

This guide walks you through the entire software localization process, from planning to production. Each section includes clear examples and highlights what makes the biggest difference to translation quality.

1. Plan Your Localization Strategy

Start by deciding which markets to target and how translations will fit into your development process.

Decide Which Markets to Target First

You don’t need to localize into 20 languages at once. Start with 2-3 markets where you have actual demand.

• Check analytics for traffic outside of English-speaking countries
• Review support tickets and feature requests for language patterns
• Align language support with your business expansion plans

Choose Your Localization Workflow

You can localize your software in different ways, and the method you choose depends on your project:

2. Use Separate Files for Localizable Content

Translation tools can’t detect hard-coded strings in your source code. Move all user-facing text into resource files. This includes:

• UI labels, buttons, and menu items
• Error messages and validation text
• Email templates and notifications
• Help text, tooltips, and placeholder text
• Success/confirmation messages

Then, use your framework’s internationalization functions to mark translatable text instead of hard-coding strings.

React example:

// Wrong - hard-coded
<button>Submit</button>

// Right - using react-intl
<button>{t('submit_button')}</button>

// Wrong - hard-coded
<button>Submit</button>

// Right - using react-intl
<button>{t('submit_button')}</button>

WordPress example:

// Wrong - hard-coded
echo 'Submit';

// Right - using WordPress i18n
echo __( 'Submit', 'your-textdomain' );

// Wrong - hard-coded
echo 'Submit';

// Right - using WordPress i18n
echo __( 'Submit', 'your-textdomain' );

Rails example:

# Wrong - hard-coded
flash[:notice] = "Profile updated successfully"

# Right - using Rails I18n
flash[:notice] = t('profile.update_success')

# Wrong - hard-coded
flash[:notice] = "Profile updated successfully"

# Right - using Rails I18n
flash[:notice] = t('profile.update_success')

Make sure to choose the file format that fits your project based on the programming language or framework you’re using. Popular file formats include:

• .json – JavaScript frameworks (React, Vue, Angular)
• .po/.pot – WordPress, PHP, Python (gettext)
• .yaml/.yml – Ruby on Rails
• .xml – Android (strings.xml)
• .xcstrings – iOS/macOS

3. Handle Placeholders and Dynamic Content

When text includes dynamic values like usernames, counts, or dates, use placeholders instead of string concatenation. Different languages have different word orders. Concatenation breaks this by splitting sentences into fragments that can’t be reordered.

Correct Examples

PO File:

msgid "Hello, %s!"
msgstr ""

msgid "Hello, %s!"
msgstr ""

JSON File:

{
  "greeting": "Hello, {name}!"
}

{
  "greeting": "Hello, {name}!"
}

YAML File:

greeting: "Hello, %{name}!"

greeting: "Hello, %{name}!"

Incorrect Example (String Concatenation)

const name = 'John';
const message = 'Hello, ' + name + '!';

const name = 'John';
const message = 'Hello, ' + name + '!';

Make sure to use placeholder syntax that works with your framework. Here are some common patterns:

Design the UI for Text Expansion and Different Languages

Text length changes dramatically across languages:

• German text is typically 30% longer than English
• French runs about 20% longer
• Asian languages like Chinese and Japanese are often shorter
• Fixed-width layouts, buttons, and navigation menus break when text expands or when you support right-to-left languages like Arabic

Before you start coding, think through how different languages impact space during the design phase and save yourself headaches down the road.

For implementation details and code examples, see our guide on preventing layout issues with long translations.

5. Write Content that Translates Well

If your content is hard to read in your original language, it will be even harder to translate. The more complex your language, the more editing you’ll need to do after translation.

✓ Write full sentences with clear subjects and actions.

Correct Example

"You have no saved items in your cart."

"You have no saved items in your cart."

This clearly states what’s empty (cart) and what it should contain (saved items).

Incorrect Example

"No cart items."

"No cart items."

This example is missing the subject (“you”) and action (“have”). These fragments could mean “There is no cart” or “Items not in cart” depending on how they’re interpreted.

✓ Keep it simple. Short, clear words produce better translations than complex vocabulary.

Correct Example

"Remove item from cart"

"Remove item from cart"

Incorrect Example

"Eliminate this article from your shopping cart"

"Eliminate this article from your shopping cart"

✓ Avoid idioms and cultural references.

Phrases like “piece of cake” or “hit a home run” don’t translate literally and may not make sense in other cultures.

6. Configure Your Application to Load Translations

Set up your application to detect the user’s language and load the appropriate translation file.

Set Up Language Detection and File Loading

Most modern frameworks include i18n libraries that handle language detection and file loading. For example:

• React with react-i18next

React doesn’t include i18n by default, so you’ll need react-i18next. Install it with npm install react-i18next i18next, then configure it to detect the browser language and load your translation files.

• Ruby on Rails

Rails includes I18n by default. Configure it in config/application.rb. Then, detect the user’s language in your ApplicationController.

• WordPress

WordPress handles language detection automatically. Users set their site language in Settings → General, and WordPress loads the corresponding .mo file from wp-content/languages/. For multilingual sites where different users need different languages, you’ll need a plugin like WPML to handle per-user language selection.

Handle Missing Translations

Set your fallback language to your primary language. When a translation file doesn’t exist or strings are missing, users see the fallback instead of broken text or translation keys.

Add a Language Switcher (If Needed)

Most applications should respect the user’s browser or device language settings automatically. But if you want to let users manually override this—common for web applications—add a language switcher and store their choice:

// Save user's manual language selection
localStorage.setItem('userLanguage', selectedLanguage);

// Check for manual selection first, then use browser default
const userLanguage = localStorage.getItem('userLanguage') || navigator.language;

// Save user's manual language selection
localStorage.setItem('userLanguage', selectedLanguage);

// Check for manual selection first, then use browser default
const userLanguage = localStorage.getItem('userLanguage') || navigator.language;

Mobile apps typically don’t include language switchers since users expect apps to follow their device settings.

7. Translate Your Resource Files

Manually sending files to translators creates a bottleneck that slows every release. Automating translation keeps all languages in sync without manual work.

PTC is an AI translation tool that automates this process. You can integrate it with your GitHub, GitLab, or Bitbucket repository, or use the API for CI/CD integration. When you update strings, translations happen automatically.

Creating an account is free, and you can translate 2,500 words into 2 languages at no cost. After that, there’s no subscription fee—you pay only for what you translate.

8. Test Localized Versions Before Launch

Testing ensures your translations display correctly and your UI works across different languages. Don’t just check if translated text appears. Also test functionality: