Localization strategy

Internationalization vs Localization: How They Differ, and Why You Need Both for Global Reach

Internationalization and localization are often confused to be the same. Let’s see how they differ and why both are important for global expansion.
Internationalization vs localization blog post featured image | Phrase

Internationalization (i18n) and localization (l10n) are 2 terms that product and development teams often encounter when creating software products for a global user base and tend to use them interchangeably. While closely related, internationalization and localization aren’t one and the same.

Internationalization aims to build globally-ready software that can easily adapt to any market’s cultural, linguistic, or legal requirements. Localization takes an internationalized product and adapts its contents (whether text, image, sound, or color) to maximize its chances of success in the target market.

To help you better understand the differences, this guide breaks down both internationalization and localization, shares examples and best practices—and explains how their combined power can enable growing businesses to launch global products that create memorable customer experiences across markets.

Internationalization vs localization: How are they different?

Internationalization and localization are complementary phases of software design and development, often mistaken for one another, happening sequentially, and essential to plan from the get-go to give a software product a strong start in the global marketplace.

Business globalization process layers | Phrase
Successfully expanding to global markets involves integrating internationalization and localization into product development

Let’s outline the main differences between internationalization and localization:

Internationalization vs localization: Key differences
Internationalization Localization

Internationalization comes first—aiming to make localization easier.


Internationalization is the process of developing a software application to support multiple languages and easily adapt to local market norms and preferences. Think of your software product as the apartment complex you, the real estate developer, are putting up for lease—you’re laying the supporting structure (including infrastructure and utilities) that the apartment building relies on. Internationalization is the foundation of a globally successful product.


Internationalization is the domain of software developers.

Localization always follows internationalization.


Localization involves adapting all elements of your global software to the needs and preferences of users in your target market—from content and user interface (UI) to images, colors, and more. Going back to the apartment complex analogy, localization is similar to refining the facade of the building and all the amenities and equipment inside to attract prospective customers.


Localization is typically handled by professional linguists (e.g., translators, editors, or proofreaders), but it also involves designers, marketing specialists, copywriters, etc.

What is internationalization (i18n)?

Internationalization is the process of designing software ready for adaptation to different regions, markets, and languages.

Often abbreviated as “i18n” (where the number 18 represents the 18 letters between “i” and “n”), internationalization covers a set of software design principles and best practices for developers to follow to ensure the final product is able to support multiple languages and account for regional settings, preferences, and norms.

Why is software internationalization important?

Internationalization is an essential phase of software development—it touches on core areas of the user experience (UX) developers want to create. Incorrectly internationalized product features can be a downright show-stopper, negatively affecting the functionality and usability of the software application.

Without software internationalization, global expansion transforms into a time-consuming and costly endeavor—and going back and reengineering the product to make it global-ready may no longer be an option in today’s fast-paced, just-in-time world of agile software development.

That being said, global expansion comes with a cost, but you can offset some by incorporating internationalization into the development process. With internationalization, the source code will be ready to support multi-lingual, multi-country expansion from the very start—or whenever you press the global launch button—and, crucially, you will afford yourself the benefit of time to strategize which market to go to next, focusing your effort where it matters.

Example of internationalization

As established, an important aspect of internationalization is ensuring the software adapts to local preferences—such as a user selecting a language from the available options in-app. This implies the app will be translated into the language and can dynamically display the content to match the user’s choice.

The sample JavaScript code below shows a possible usage scenario where the app retrieves the correct translation of a confirmation message (“Are you sure?” in English) based on the user’s language (French in this example).

// Assume that 't' is a function for translation

// English version
const englishTranslations = {
  confirmationMessage: 'Are you sure?',
  // Add more translations as needed
};

// French version
const frenchTranslations = {
  confirmationMessage: 'Êtes-vous sûr ?',
  // Add more translations as needed
};

// Function to get the translated text
function t(key, language) {
  const translations = language === 'en' ? englishTranslations : language === 'fr' ? frenchTranslations : {};
  return translations[key] || key; // Return the translation or the key itself if not found
}

// Example usage in the dashboard
const dashboardLanguage = 'en'; // Assume this is dynamically set based on user preferences

// Using internationalization for confirmation message
const userConfirmed = confirm(t('confirmationMessage', dashboardLanguage))Code language: JavaScript (javascript)

The original key, confirmationMessage, in English (“Are you sure?), changes to the French equivalent (“Êtes-vous sûr ?”) with the following bit of internationalized code:

const userConfirmed = confirm(t('confirmationMessage', dashboardLanguage))

What are some best practices for internationalization?

Best practices for internationalization can be drawn into a handy, easy-to-follow checklist for developers:

Internationalization best practices: The developer’s checklist

Use the correct character encoding (e.g., UTF-8) to facilitate multilingual support for the product.


Plan with text expansion for non-English languages for key CTAs or error message boxes (e.g., German words generally have a greater number of letters compared to English ones).


Determine your languages pairs—different MT engines are more suitable for certain language pairs than others.


Separate translatable text from the source code or images.


Use separate resource files for anything requiring translation (e.g., titles, product names, error messages, etc.).


Avoid hard-coding numbers, units, dates, and times. A classic example is the US date formatting of MM/DD/YYYY, which may not be understood in other parts of the world and will require adapting to the local standard.


Mirror the user interface (UI) for right-to-left (RTL) languages like Arabic or Hebrew.

Screen of Facebook's homepage in Arabic | Phrase
An example of Facebook’s user interface mirrored for Arabic audiences © Facebook

What is localization (l10n)?

Localization is the process of adapting products or services to the culture and language of customers in different target markets.

Usually shortened to “l10n” (the number 10 represents the letters between “l” and “n”), localization goes beyond mere translation. Translation aims to accurately transfer words from one language to another, preserving the meaning of the original text. Localization goes a step further, adapting the entirety of a product to the cultural specifics of the target market.

How does localization work?

Launching a global product means more than just transferring it from one language to another. Depending on the nature of the product, there are different forms of localization, each with its standardized procedures and desired outcomes.

Main localization types
Software localization Adapting software to meet the linguistic, cultural, and functional requirements of a specific target market, ensuring a seamless user experience.
Website localization Modifying a website’s content, design, and functionality to suit the preferences and expectations of users in a particular geographic region or cultural context.
Marketing localization Tailoring marketing materials, campaigns, and strategies to resonate with the cultural nuances and preferences of a specific target audience, enhancing engagement.
Product localization Customizing a product’s features, packaging, and presentation to align with the cultural and linguistic expectations of a particular market, optimizing its appeal and usability.
Game localization Adapting video games to the linguistic, cultural, and regulatory requirements of different markets, providing an immersive and enjoyable gaming experience for diverse audiences.

Localization is a team effort involving experts from various fields—linguists, terminologists, localization engineers, designers, language testers, etc. It follows a multistage workflow, leveraging both human skills and the latest technologies like translation management systems (TMS) or machine translation (MT)—to name just a few key elements of the typical localization ecosystem.

What is a translation management system?

Learn what makes a translation management system and how it helps businesses seeking to expand globally translate content more quickly and efficiently.

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Example of localization done right

The most successful global brands recognize the importance of tailoring the UX to align with the expectations of users in different markets. Put another way, UX localization isn’t just about translating text on the screen. Visuals and colors are equally important.

Take a look at the side-by-side view of the English and Japanese versions of Sony’s website below to see how the company applies decades of experience in localization to craft a natural UX for its international audiences.  

The immediate takeaway is a pronounced contrast in information density between the .jp website version on the right and the .com version on the left. The Japanese website features many text-heavy images. This is because consumers in Japan and other Asian markets have a preference for content that is information-rich, while Western markets tend to lean towards a more minimalist visual design.

Screens of Sony's homepage in English and Japanese | Phrase
A side-by-side comparison of Sony’s English (.com) and Japanese localized websites reveals clear visual differences tailored to each audience’s preferences

Localization best practices

The holy grail for any product or service—whether digital or physical—is to continue expanding the user base and monetizing well into its lifetime. Localization is vital to unlock long-term growth opportunities on a global scale.

Here are 5 tried-and-tested strategies that can maximize your localization ROI (return on investment) in the long run:

  • Prioritize your markets and languages. Different markets will have varying preferences for localized content—and in some, companies can get away with English only. Similarly, not all content is created equal and will require different levels of attention. You don’t need to do everything at once with localization. Learn to prioritize.
  • Create an equitable customer experience. You want to create the same seamless, natural user experience for non-English speakers as for those who speak English—it’s all about the end user.
  • Create content with localization in mind. Cultivate a global-first mindset by including localization best practices early in the product design phase. This way, you avoid unnecessary rework and save time and money.
  • Listen to what the market says. Work with local subject matter experts from sales or marketing in each market and tap into user data to guide and enhance your localization strategy.
  • Tech is your ally. Localization works best when relying on technology to drive efficiencies and improve time to market. That’s why it’s a smart move to place a cloud-based translation management system at the heart of your localization endeavors.
Phrase TMS | Phrase

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Internationalization and localization are critical to global expansion

Securing a stronghold in the domestic market is a solid goal for a young company. Still, as it evolves, the gaze naturally turns towards global horizons. Essential to this expansion journey are internationalization and localization—2 key players that set the stage for successful globalization.

Internationalization prepares your product for efficient deployment across diverse markets. Localization guarantees a smooth user experience, making customers want to come back for more. It’s the dream scenario for any company eyeing lasting success on the global stage.

Thanks to localization technology, internationalization and localization have become more straightforward and accessible, so choosing a technology partner that can support you on both fronts is the most reliable way to expand your reach, foster deeper connections, and drive global growth.

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