XLIFF

XLIFF (XML Localization Interchange File Format) is an XML-based bitext format created to standardize the way localizable data are passed between and among tools during a localization process and a common format for CAT tool exchange. The XLIFF Technical Committee (TC) first convened at OASIS in December 2001 (first meeting in January 2002),^[2] but the first fully ratified version of XLIFF appeared as XLIFF Version 1.2 in February 2008. Its current specification is v2.2^[1] released on 2025年03月13日, which is backwards compatible with v2.1 released on 2018年02月13日.

The specification is aimed at the localization industry. It specifies elements and attributes to store content extracted from various original file formats and its corresponding translation. The goal was to abstract the localization skills from the engineering skills related to specific formats such as HTML.^[3]

XLIFF is part of the Open Architecture for XML Authoring and Localization (OAXAL) reference architecture.

The XLIFF Technical Committee (TC) has released XLIFF Version 2.2.^[4] Prior to making of the major new version 2.0, feedback was gathered from XLIFF's user community which was integrated into the following generation version of the standard. Two of the primary methods used included compiling a list of extensions used by XLIFF toolmakers, and compiling a list of XLIFF features supported by each XLIFF tool.

• Makers of XLIFF tools have taken advantage of XLIFF's extensibility mechanism in order to implement a number of features. By collecting a list of these extension points and analyzing them for common tasks, the XLIFF TC hopes to improve the XLIFF 2.0 Specification to include mechanisms that will enable the toolmakers to support these features without using extensibility.
• Makers of XLIFF tools have supported different sets of features in the XLIFF 1.2 Specification. By compiling a list of these features, the XLIFF TC hopes to identify areas where the XLIFF 2.0 Specification can be improved to enable toolmakers to more widely support the specification.

On March 13, 2025 XLIFF 2.2 became an OASIS Specification.

On July 2024, XLIFF 2.1 was approved as ISO 21720:2024.^[5]

On February 13, 2018 XLIFF 2.1 specification became an OASIS Standard.^[6]

In November, 2017 XLIFF 2.0 specification was approved as ISO 21720:2017.^[7]

On August 6, 2014 the XLIFF 2.0 specification became an OASIS Standard.^[8]

On May 6, 2014, the XLIFF 2.0 specification was moved^[9] to Candidate OASIS Standard.^[10]

Example of an XLIFF 2.0 document:

<xliffxmlns="urn:oasis:names:tc:xliff:document:2.0"version="2.0"srcLang="en-US"trgLang="ja-JP">
<fileid="f1"original="Graphic Example.psd">
<skeletonhref="Graphic Example.psd.skl"/>
<unitid="1">
<segment>
<source>Quetzal</source>
<target>Quetzal</target>
</segment>
</unit>
<unitid="2">
<segment>
<source>AnapplicationtomanipulateandprocessXLIFFdocuments</source>
<target>XLIFF文書を編集、または処理するアプリケーションです。</target>
</segment>
</unit>
<unitid="3">
<segment>
<source>XLIFFDataManager</source>
<target>XLIFFデータ・マネージャ</target>
</segment>
</unit>
</file>
</xliff>

An XLIFF 1.2^[11] document is composed of one or more <file> elements. Each <file> element corresponds to an original file or source (e.g. database table). A <file> contains the source of the localizable data and, once translated, the corresponding localized data for one, and only one, locale.

Localizable data is stored in <trans-unit> elements. The <trans-unit> element holds a <source> element to store the source text, and a <target> element to store the latest translated text. The <target> elements are not mandatory.

<trans-unitid="1">
<sourcexml:lang="en">Cannotfindthefile.</source>
<targetxml:lang="fr">Fichiernontrouvé.</target>
</trans-unit>

The example below shows an XLIFF document storing text extracted from a Photoshop file (PSD file) and its translation to Japanese:

<xliffversion="1.2">
<fileoriginal="Graphic Example.psd"
source-language="en-US"target-language="ja-JP"
tool="Rainbow"datatype="photoshop"
>
<header>
<skl>
<external-fileuid="3BB236513BB24732"href="Graphic Example.psd.skl"/>
</skl>
<phase-group>
<phasephase-name="extract"process-name="extraction"
tool="Rainbow"date="20010926T152258Z"
company-name="NeverLand Inc."job-id="123"
contact-name="Peter Pan"contact-email="ppan@example.com"
>
<note>MakesuretousetheglossaryIsentyouyesterday.Thanks.</note>
</phase>
</phase-group>
</header>
<body>
<trans-unitid="1"maxbytes="14">
<sourcexml:lang="en-US">Quetzal</source>
<targetxml:lang="ja-JP">Quetzal</target>
</trans-unit>
<trans-unitid="3"maxbytes="114">
<sourcexml:lang="en-US">AnapplicationtomanipulateandprocessXLIFFdocuments</source>
<targetxml:lang="ja-JP">XLIFF文書を編集、または処理するアプリケーションです。</target>
</trans-unit>
<trans-unitid="4"maxbytes="36">
<sourcexml:lang="en-US">XLIFFDataManager</source>
<targetxml:lang="ja-JP">XLIFFデータ・マネージャ</target>
</trans-unit>
</body>
</file>
</xliff>

• Internationalization Tag Set (ITS)
• OpenTMS (Open Source Translation Management System)
• Segmentation Rules eXchange (SRX)
• TermBase eXchange (TBX): an XML format for the exchange of terminology data, "an industry standard for terminology exchange"
• Translation Memory eXchange (TMX)

• OASIS XLIFF TC Charter
• OASIS XLIFF Technical Committee Web site
• XLIFF mailing lists: TC List, Comments to TC List, Users List
• XLIFF Validation Service
• Multilingual App Toolkit (MAT) from Microsoft