---
title: "What is the difference between XLIFF 1.2 and XLIFF 2.0, and how do I convert between them?"
description: "XLIFF 1.2 (2008) uses <trans-unit> with the languages on <file>; XLIFF 2.0 (2014) and 2.1 (2018) use <unit> and <segment>, put srcLang and trgLang on the root, and are not backward compatible. Changing the version attribute does not convert a file; re-export it or convert with Okapi."
category: xliff
date: 2026-10-09
canonical: https://localizely.com/i18n-questions/xliff/what-is-the-difference-between-xliff-1-2-and-xliff-2-0-and-how-to-convert/
---

# What is the difference between XLIFF 1.2 and XLIFF 2.0, and how do I convert between them?

They are two different XML vocabularies that share a name. XLIFF 1.2 became an OASIS Standard in February 2008; XLIFF 2.0 followed in August 2014 and was revised as 2.1 in February 2018. The 2.x specification states that its documents cannot be conformant to 1.2 and that 2.x applications are not required to read 1.2. Editing `version="1.2"` to `version="2.0"` therefore produces a file that is valid in neither: the namespace, the element names and the structure all differ.

The main differences:

- Structure: 1.2 nests `<xliff>`, `<file>`, `<body>`, `<trans-unit>` with `<source>` and `<target>`; 2.x nests `<xliff>`, `<file>`, `<unit>`, `<segment>` with `<source>` and `<target>`, and a unit may be split into several segments.
- Languages: 1.2 puts `source-language` and `target-language` on each `<file>`; 2.x puts `srcLang` and `trgLang` once on the root.
- Namespace: `urn:oasis:names:tc:xliff:document:1.2` versus `urn:oasis:names:tc:xliff:document:2.0` (2.1 keeps the 2.0 namespace with `version="2.1"`).
- Inline codes: `<g>`, `<x/>`, `<bpt>`/`<ept>`, `<ph>` in 1.2; `<pc>`, `<ph>`, `<sc>`/`<ec>` with the original markup in `<originalData>` in 2.x.
- Workflow state: 1.2 has ten `state` values on `<target>` (`new`, `translated`, `signed-off`, `final` and others) plus `approved` on `<trans-unit>`; 2.x has four on `<segment>`: `initial`, `translated`, `reviewed`, `final`.
- Modules: 2.x adds optional modules for translation candidates, glossaries, metadata, format style, size restrictions and validation.

```xml
<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
  <file original="app" source-language="en" target-language="de" datatype="plaintext">
    <body>
      <trans-unit id="greeting">
        <source>Hello</source>
        <target state="translated">Hallo</target>
      </trans-unit>
    </body>
  </file>
</xliff>
```

```xml
<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="de">
  <file id="f1">
    <unit id="greeting">
      <segment state="translated">
        <source>Hello</source>
        <target>Hallo</target>
      </segment>
    </unit>
  </file>
</xliff>
```

Which one you get is decided by the exporter. Xcode writes 1.2 (its XLIFF uses `<trans-unit>`), Angular's `ng extract-i18n` writes 1.2 by default and 2.0 with `--format=xlf2`, and Symfony's `translation:extract` defaults to `xlf12` with `xlf20` as the alternative. Poedit and OmegaT open both; parts of Okapi's XLIFF 2 support are still documented as experimental, so 1.2 is the safer choice when the receiving tool is unknown.

Converting an existing file: prefer re-exporting from the source tool in the version the consumer accepts, because the exporter knows the original ids and placeholders. If you only have the file, the [Okapi Framework](https://okapiframework.org/) reads both versions through its XLIFF and XLIFF-2 filters and writes either: Rainbow's Translation Kit Creation step offers a Generic XLIFF (1.2) and an XLIFF 2.0 package format, and Tikal's `tikal -x` extracts any supported input, including an XLIFF 2 document, into a 1.2 file that `tikal -m` merges back after translation. Check ids, notes and inline codes afterwards; Okapi's own docs list comments and original formatting as things the XLIFF 2 round trip loses. If a tool only accepts 1.2, export 1.2 at the source and skip the conversion.

Source: https://localizely.com/i18n-questions/xliff/what-is-the-difference-between-xliff-1-2-and-xliff-2-0-and-how-to-convert/