Key takeaways
- The W3C defines localisation as adapting a product or content to the language, cultural and other requirements of a specific target market, or locale.
- The W3C defines internationalisation as design and development that enables easy localisation for audiences that vary in culture, region or language.
- Localisation is abbreviated l10n and internationalisation i18n, from the number of letters between the first and last letters of the English words.
- Internationalisation is done once, by developers, before localisation; localisation is then repeated for every target market.
- Transcreation and culturalisation are specialised forms of adaptation that sit within localisation.
These three terms are often used as if they meant the same thing, which leads to mismatched quotes and missed work. This article is for anyone briefing a translation provider or planning a product launch abroad, whether the product is a document, a website, an app or a game.
Below you will find a plain definition of each term, a side-by-side comparison, an example that follows one feature through all three stages, and guidance on which your project needs.
What is translation?
Translation is the conversion of written text from one language (the source) into another (the target), keeping its meaning, tone and purpose. It works on the words: a professional translator renders the content accurately and naturally, but does not usually change images, layouts, prices or product features.
Translation is the core of most language projects and is often all that is needed for documents such as contracts, reports or certificates. For a fuller picture of the service, see our translation services page.
What is localisation?
Localisation is the adaptation of a whole product or piece of content for a specific market, of which translation is one part. The World Wide Web Consortium (W3C) defines it this way:
"Localization refers to the adaptation of a product, application or document content to meet the language, cultural and other requirements of a specific target market (a locale)." (W3C: Localization vs. Internationalization)
The W3C lists what this can involve, including "Numeric, date and time formats", "Use of currency", "Symbols, icons and colors", "Varying legal requirements" and "Address and contact information formats". A locale is a combination of language and region, such as French in Canada or Spanish in Mexico.
What is internationalisation?
Internationalisation is the design and engineering work that makes a product ready to be localised, so that new languages can be added without changing the code. The W3C defines it as "the design and development of a product, application or document content that enables easy localization for target audiences that vary in culture, region, or language."
In practice, internationalisation means supporting Unicode, keeping user-facing text out of the code, avoiding sentences built from fragments, allowing for text expansion and right-to-left scripts, and using locale-aware formatting for dates, numbers and currencies. Our guide to software and UI string localisation gives the detailed rules.
Two figures show why this groundwork matters. IBM guidance published by the W3C expects English strings of up to 10 characters to expand by 200–300% in translation (W3C: Text size in translation), so fixed-width layouts break. And the Unicode CLDR project defines six plural categories, from "zero" to "other" (Unicode CLDR: Plural Rules), so code that only knows singular and plural fails in many languages.
Why are they written l10n and i18n?
The abbreviations l10n and i18n are numeronyms that count the letters between the first and last letters of the English words. The W3C explains that localisation "is sometimes written in English as l10n, where 10 is the number of letters in the English word between l and n", and internationalisation as i18n for the 18 letters between i and n.
You may also see g11n for globalisation, an umbrella term for the business strategy of taking a product to international markets, which includes internationalisation and localisation.
Translation vs localisation vs internationalisation: what is the difference?
The three differ in what they change, who does the work and when it happens. The table summarises the differences.
| Aspect | Translation | Localisation | Internationalisation |
|---|---|---|---|
| What it changes | The words | Words, formats, images, references, legal and commercial details | The code, design and content architecture |
| Who usually does it | Translators and reviewers | Translators, reviewers, designers, testers and local specialists | Developers, designers and content architects |
| When it happens | Whenever content needs another language | For each target market, before launch and with every update | Once, early in development, before localisation |
| How often | Per document or update | Repeated for every locale | Done once, then maintained |
| Typical output | A translated document or file | A product or site that feels local | A product that can accept any language |
| Typical example | A contract translated into German | A shop adapted for Mexico, with pesos and local delivery terms | An app rebuilt to support Arabic right-to-left layouts |
How do the three work together on a real feature?
The three stages build on each other, and following one feature through them shows why the order matters. Take a delivery date shown on an online checkout page.
- Internationalisation: the developer stores the date as data and formats it with a locale-aware library, instead of hard-coding "Delivered by 12/03". The message "Delivered by {date}" goes into a resource file as one complete string.
- Translation: the translator renders "Delivered by {date}" into French, German or Japanese, moving the placeholder where each grammar requires.
- Localisation: each locale shows the date in its own format, the delivery promise is checked against local carriers, and the surrounding returns information is adapted to local consumer rules.
If step 1 is skipped, steps 2 and 3 either fail or need costly code changes for every language.
Where do transcreation and culturalisation fit?
Transcreation and culturalisation are specialised forms of adaptation that sit inside localisation. They are used when the content itself, not only its language, has to change for a market.
- Transcreation recreates marketing messages, slogans and creative copy so that they have the same effect in another language, even if the words change completely. See transcreation vs translation.
- Culturalisation reviews and changes visual, narrative or gameplay content, such as symbols, maps and gestures, so that it is acceptable and legal in each market. See game culturalisation.
Which one does your project need?
The service you need depends on what you are adapting and how it will be used. Use these cases as a guide.
Documents
Contracts, reports, manuals and certificates usually need translation only, sometimes with formatting of dates and units. Legal or official documents may also need certification.
Websites and marketing
Websites need localisation: translated content plus adapted prices, legal pages, imagery and search metadata. Campaign copy often needs transcreation. See our guide to website localisation.
Software, apps and games
Software products need all three. Internationalisation comes first, then translation and localisation for each market, followed by in-context testing. For games, our complete guide to video game localisation covers the full process.
Common mistakes when buying these services
Most problems come from asking for one service when the project needs another. Watch for these:
- Requesting "translation" for an app, then discovering the code cannot display the translated text.
- Treating internationalisation as the translator's job, when it is an engineering task.
- Localising a website without adapting prices, legal pages or images.
- Translating slogans literally instead of transcreating them.
- Comparing quotes for different scopes as if they were like for like.
How TranslationWorks can help
TranslationWorks is a UK-based translation agency that provides translation and transcreation in 150+ languages, using native-speaking linguists. Our translation services cover documents, websites and software text; our transcreation service adapts marketing and creative copy; and our IT and gaming translation team works on software, apps and games.
If you are not sure which service your project needs, describe what you are adapting and for which markets, and we will recommend a scope. We are ISO 17100 certified, ISO 9001 and ISO 27001 registered and Cyber Essentials certified. Request a free quote and we will reply within 24 hours.
