XLIFF (XML Localization Interchange File Format) is a standardized XML format built to exchange translatable text and segment status between CAT tools and translation management systems.
Why XLIFF Matters
XLIFF matters because it gives localization tools a common, structured way to hand translatable content back and forth without losing information. The format is most commonly used as XLIFF 1.2, still the version most widely supported across CAT tools and TMS platforms today. A file exported from one CAT tool or TMS as XLIFF carries its source and target text inside <trans-unit> elements, each with a segment ID, a state attribute tracking translation status, and any notes or context metadata a translator or developer attached — all of which a different tool can read without guessing at structure.
Because XLIFF is already an XML format designed for this exchange, translating an XLIFF file doesn’t require converting it to another format first the way some file types do. A translation system reads the file directly, replaces the text inside each <target> element, and hands back a file with the same trans-unit structure, segment IDs, and metadata intact — a round-trip that keeps XLIFF useful as an interchange format between systems built by different vendors.
XLIFF is used almost exclusively in localization pipelines rather than by end users directly — localization teams, translation agencies, and software developers moving content between a CAT tool, a TMS, and version control, often programmatically rather than one file at a time.
A Concrete Example
A software company’s TMS exports the UI strings for its next release as an XLIFF file, with each string as a <trans-unit> carrying a segment ID and a character-limit note for the button label. A translation system reads the file, translates the text inside each <target> element using the project’s translation memory and glossary, and returns the same XLIFF file with every trans-unit, segment ID, and note preserved — ready to import straight back into the TMS the export came from.
How XLIFF Works in Taia
Taia translates XLIFF files directly, with no conversion step, preserving trans-unit structure, segment IDs, and metadata; XLIFF translation requires the Pro plan or Enterprise, since it’s grouped with other specialized localization formats outside Free and Basic. See Translate XLIFF Files for the full walkthrough, including how AI and professional translation both apply to XLIFF content and how Taia’s API handles XLIFF moved programmatically between systems.