---
title: "Localization"
manual: "TYPO3 Explained"
version: "12.4"
permalink: "https://docs.typo3.org/permalink/t3coreapi:localization@12.4"
source: "ApiOverview/Localization/Index.rst"
rendered: "2026-10-21T15:29:37+00:00"
---

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# Localization {#localization}

Except for some low level functions, TYPO3 uses localizable
strings for labels displayed in the backend. This means that the whole user
interface can be translated. The encoding is strictly UTF-8.

The default language is American (US) English, and the Core ships only with such
labels (and so should extensions).

All labels are stored in [XLIFF format](https://docs.typo3.org/permalink/t3coreapi:xliff@12.4), generally located in the
`Resources/Private/Language/` folder of an extension (old locations
may still be found in some places).

The format, TYPO3 specific details and managing interfaces of XLIFF are
outlined in detail in this chapter.

-   [Supported languages](https://docs.typo3.org/permalink/t3coreapi:supported-languages@12.4)
-   [Managing translations](https://docs.typo3.org/permalink/t3coreapi:managing-translations@12.4)
-   [Translation servers](https://docs.typo3.org/permalink/t3coreapi:translation-servers@12.4)
    -   [Localization with Crowdin](https://docs.typo3.org/permalink/t3coreapi:localization-with-crowdin@12.4)
        -   [Extension integration](https://docs.typo3.org/permalink/t3coreapi:integrate-crowdin-in-your-extension@12.4)
        -   [Mass approval](https://docs.typo3.org/permalink/t3coreapi:mass-approval-on-crowdin@12.4)
        -   [Online translation](https://docs.typo3.org/permalink/t3coreapi:online-translation-with-crowdin@12.4)
        -   [Workflow](https://docs.typo3.org/permalink/t3coreapi:workflow-from-new-crowdin-translations-to-the-typo3-installation@12.4)
        -   [Crowdin Best Practice](https://docs.typo3.org/permalink/t3coreapi:crowdin-best-practice@12.4)
        -   [Frequently asked questions (FAQ)](https://docs.typo3.org/permalink/t3coreapi:frequently-asked-questions-faq@12.4)
    -   [Custom translation servers](https://docs.typo3.org/permalink/t3coreapi:custom-translation-servers@12.4)
-   [Localization API](https://docs.typo3.org/permalink/t3coreapi:localization-api@12.4)
    -   [LanguageService](https://docs.typo3.org/permalink/t3coreapi:languageservice@12.4)
    -   [LanguageServiceFactory](https://docs.typo3.org/permalink/t3coreapi:languageservicefactory@12.4)
    -   [Locale](https://docs.typo3.org/permalink/t3coreapi:locale@12.4)
    -   [LocalizationUtility (Extbase)](https://docs.typo3.org/permalink/t3coreapi:localizationutility-extbase@12.4)
-   [XLIFF Format](https://docs.typo3.org/permalink/t3coreapi:xliff-format@12.4)
-   [XLIFF Api](https://docs.typo3.org/permalink/t3coreapi:xliff-api-access-language-labels@12.4)