# XLIFF

Source: https://traduq.com/glossary/xliff · Updated October 14, 2026

**XLIFF** (XML Localization Interchange File Format) is the OASIS standard XML format for bilingual translation files, in which a [CAT tool](https://traduq.com/glossary/cat-tool) stores each source segment with its translation, status and notes, separate from the original document's layout.

## How XLIFF is used

Translators rarely translate a Word file, a website or an app's strings directly. A CAT tool or a developer's tool first extracts the text into an XLIFF file, the translation happens there, and the translated XLIFF is then merged back into the original format. Because the layout stays outside the XLIFF, the translator cannot break it.

Each segment in the file holds the source, the target (empty until translated), a status such as new, translated or final, and optional notes. Formatting inside a sentence is kept as tags that must survive in the translation.

## Versions and variants

XLIFF 1.2 and XLIFF 2 are both in use, and most CAT tools still build on 1.2. Several tools save their own flavour of it:

- **SDLXLIFF:** Trados Studio
- **MQXLIFF:** memoQ
- **MXLIFF:** Phrase
- **TXLF:** Wordfast Pro

They add tool-specific data, such as match scores and segment locks, so they open fully in the tool that made them and partly elsewhere. memoQ, for example, opens SDLXLIFF files from Trados.

## XLIFF, TMX and TBX

XLIFF is the working file for one job. [TMX](https://traduq.com/glossary/tmx) carries the translation memory built from many jobs, and TBX carries terminology from a [termbase](https://traduq.com/glossary/termbase). Our post on [XLIFF, TMX and TBX](https://traduq.com/blog/xliff-tmx-tbx-formats-explained) explains the three side by side.

## Example

An agency sends you a Trados package with a user manual as SDLXLIFF. You translate it in your CAT tool, then, before returning it, you run a QA check: numbers, tags, terminology and punctuation, segment by segment. The agency imports the SDLXLIFF back into Trados and generates the translated manual with its original layout.

TraduQ's free tools read XLIFF in the browser, without uploading it: the [QA checker](https://traduq.com/tools/qa-checker) for XLIFF, SDLXLIFF, MQXLIFF and MQXLZ, the [converter](https://traduq.com/tools/tmx-converter) to review a file as an Excel sheet, and the [word count and quote tool](https://traduq.com/tools/translation-quote). See [how to QA check XLIFF files](https://traduq.com/blog/qa-check-xliff-files).

## Try it

- [Translation QA checker](https://traduq.com/tools/qa-checker) — Check numbers, tags, spaces and consistency in bilingual files.
- [TMX and XLIFF converter](https://traduq.com/tools/tmx-converter) — TMX, XLIFF, SDLXLIFF and PO to Excel or CSV, and back.
- [Word count & quote](https://traduq.com/tools/translation-quote) — Count words by match band against your TM or CAT report, price the job and download the quote PDF.

## Related terms

- [TMX](https://traduq.com/glossary/tmx)
- [CAT tool](https://traduq.com/glossary/cat-tool)
- [Translation memory](https://traduq.com/glossary/translation-memory)
- [Termbase](https://traduq.com/glossary/termbase)

## Related guides

- [memoQ vs Smartcat vs Wordfast for a Small Agency (2026)](https://traduq.com/blog/memoq-vs-smartcat-vs-wordfast) — memoQ, Smartcat or Wordfast for a small translation agency? 2026 prices, team costs, shared TMs, Trados file support and which fits your agency.
- [Best Trados Alternatives in 2026 for Freelance Translators](https://traduq.com/blog/trados-alternatives) — Trados Studio alternatives for freelancers in 2026: memoQ, Wordfast Pro, Phrase TMS, CafeTran, OmegaT and MateCat on price, Mac and Trados files.
- [Wordfast vs Trados Studio (2026): Price, Features, Mac](https://traduq.com/blog/wordfast-vs-trados) — Wordfast Pro or Trados Studio? 2026 prices, three-year cost, Mac and Linux support, Trados packages, TM features and which to pick.