Categories: Internationalization

i18n vs l10n — what’s the diff?

Internationalization (i18n).
Localization (l10n).
Globalization (g11n).
Localizability (l12y).

What does it all mean? In this business, there are so many alphanumeric acronyms that it can be really difficult to keep them all together. So where is the line drawn between some of these, like i18n and l10n for example?

I believe W3C said it best when they wrote the following:

Internationalization is 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.

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).”

In other words, i18n allows applications to support and satisfy the needs of multiple locales, thus “enabling” l10n. It is because of i18n that we are able to localize all of the Mozilla project within its pantheon of applications and open the web up to the world!

Believe it or not, the Mozilla project has a long history of using i18n as the base for the L10n of its products. After some digging through the Mozilla doc archives, I found this gem, which briefly discusses the role of i18n and l10n at Mozilla since its inception. Pretty cool, right?

Now, say you wanted to get involved more directly in Mozilla i18n. What could you do? Since a lot of the i18n groundwork has already been laid, it can be difficult finding where one could contribute to this area. After some careful consideration, however, here are some ideas:

  • Study up on Mozilla i18n (or localizability) infrastructure and write about it in the MDN.
  • Test your localizations for i18n-related bugs, like any character issues (e.g., character input, direction, display, UI real estate, etc.).
  • If you find i18n problems, file those bugs!
  • Talk to the l10n-drivers about where there might be a need.

Want to know more or have something on your mind about i18n? Please comment!

W3C International. World Wide Web Consortium. Retrieved 2011-12-13.

9 comments on “i18n vs l10n — what’s the diff?”

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  1. Milad wrote on



  2. Selena wrote on

    If you’re interested to localize web software, PC software, mobile software or any other type of software, I warmly recommend this web-based l10n tool:


  3. Tonda wrote on

    As I understand it, localization means providing user interface translations in different languages, internationalization is allowing users to use their native date, number, currency etc. formats.

    Personally I prefer products localized to english (since translations to my native language are frequently poor, inconsistent – different translators use different terminology – and confusing) but internationalized to my native language. Microsoft products mostly allow this while Google joins this into one option so having US english translation also means to have their illogical date field ordering.


    1. Miles Raymond wrote on

      I’m glad I’m not the only one that find’s US date format as illogical and confusing.


      1. Sandra wrote on

        Hi, I have a similar opinion/experience as both above comments. I have found turning US off and UK English on can make a world of difference.

        It also helps when sites/apps don’t try to guess or assume the locale or language I want to use. Using a Dutch Google chrome browser sometimes makes it almost impossible to use Google Spreadsheets in a different cultural setting, without creating additional Google accounts or jumping through other hoops.

        As a developer, I try to promote the use of ISO 8601, standardising the use of dates to e.g. 2017-05-18.


      2. John Currier wrote on

        Most people in the US tend to say dates in this manner: “November 20th, 2021”, so it somewhat makes sense that the printed version (12-20-2021) would match that pattern. Swapping month and day makes it slightly better, but is the exact opposite of how we render time (least-specific (hour) to most specific (minutes/seconds)).

        The ISO 8601 approach (2021-12-20) is consistent with how we render time and readily sortable.


  4. Bits wrote on

    Very well written article, that defines the various terms in the Globalization world in one of simplest forms.
    Leandro – thanks for sharing!


  5. Adriana Grande wrote on

    Great article Jeff!

    I’ve been looking more and more into the “marriage” UX & L10N and you nailed from the title! Thanks!



  6. Svard Von Bektroad wrote on

    Most often I right dates as: 2022-03-09 . That way they sort chronologically when sorted alphabetically or numerically. I avoid the rite of dates as either 9 March 2022,nor March 9 2022. But you write as you will.


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