January 14, 2026 | 5 min Read
XLIFF: The Universal Translation Standard Your Team Should Know
Every translation tool has its own internal format. Phrase uses one structure, Lokalise another, MemoQ another still. When you need to move content between tools—or work with external translators who use different tools—these incompatibilities create friction.
XLIFF exists to solve this problem.
What XLIFF actually is
XLIFF—XML Localization Interchange File Format—is an OASIS standard designed specifically for exchanging localization data between tools. Think of it as the PDF of translation: a format that preserves content and structure regardless of what tool created it or what tool will use it.
A simplified XLIFF structure looks like:
<xliff version="1.2">
<file source-language="en" target-language="de">
<body>
<trans-unit id="1">
<source>Welcome to our application</source>
<target>Willkommen in unserer Anwendung</target>
</trans-unit>
</body>
</file>
</xliff>
Each trans-unit contains a source segment and its translation. Metadata travels with the content: which file it came from, what state the translation is in, translator notes, quality scores.
The format handles complexity too: inline formatting tags, segmentation information, terminology references, translation memory matches.
Why XLIFF matters for workflow flexibility
Without a common interchange format, you’re locked into whatever tool you start with. Want to send content to a freelancer who uses a different CAT tool? Export, hope the format transfers, import, hope nothing breaks. Want to switch platforms? Painful data migration.
With XLIFF:
Tool independence. Your content isn’t trapped in proprietary formats. You can work with any tool that supports XLIFF—which is essentially all professional translation tools.
Freelancer flexibility. External translators can use their preferred tools. You send XLIFF, they translate in whatever environment they’re comfortable with, they return XLIFF.
Quality assurance options. You can run XLIFF through QA tools different from your translation environment. Specialized QA platforms often accept XLIFF directly.
Archive portability. Years from now, if you need to access old translations, XLIFF files remain readable. Proprietary formats from discontinued products may not.
XLIFF 1.2 vs 2.0
Two main versions exist in production use:
XLIFF 1.2 is the established standard with near-universal support. Every major translation tool can read and write it. It’s stable, well-documented, and has known quirks that the industry has learned to work around.
XLIFF 2.0 is the modernized standard with cleaner architecture and better extensibility. Support is growing but not yet universal. Some tools read 2.0 but write 1.2. Some handle both. Some only support 1.2.
For maximum compatibility, 1.2 remains the safer choice. For newer workflows built on tools with strong 2.0 support, the newer version offers advantages.
The practical difference:
- If you’re exchanging files with many different parties, use 1.2
- If you control both ends of the workflow and your tools support 2.0, consider it
- If unsure, 1.2 won’t fail you
Generating XLIFF from source files
XLIFF isn’t a source format—you don’t create XLIFF documents the way you create Word documents. It’s generated from source files during the localization process.
The generation flow:
- Source file (Word, HTML, XML, etc.) enters the system
- Extraction filter parses the file, identifying translatable content
- XLIFF generation creates the interchange file with source content and structure metadata
- Translation happens in whatever tool or workflow
- XLIFF return brings translated content back
- Reinsertion produces the translated version of the original file
The XLIFF serves as the vehicle for the translation journey. The original format stays intact for final delivery.
What XLIFF preserves (and doesn’t)
XLIFF captures:
- Source and target text
- Segment boundaries
- Inline formatting (bold, italic, links, etc. as tags)
- Translation state (translated, needs review, approved, etc.)
- Notes and comments
- File and segment identifiers
XLIFF doesn’t capture:
- Visual layout (page breaks, columns, positioning)
- Non-textual content (images, charts) except as references
- Application-specific behaviors
This is intentional. XLIFF carries the linguistic content that needs translation. Visual and behavioral elements stay in the source format and get reunited with the translated text during reinsertion.
Working with XLIFF in practice
If your workflow involves XLIFF exchange, some practices help:
Validate before sending. XLIFF is XML, and XML can be malformed. Validation catches structural problems before they cause downstream failures.
Preserve file references. XLIFF files reference their source files. If those references break (file renamed, path changed), reinsertion becomes problematic.
Mind the version. When exchanging with external parties, confirm which XLIFF version they expect. Version mismatch is a common source of import failures.
Watch for tool-specific extensions. Tools often add custom data to XLIFF files beyond the standard elements. This extra data usually survives round-trips through other tools, but occasionally it doesn’t. Test your specific tool combinations.
XLIFF as platform escape hatch
One underappreciated benefit of XLIFF fluency: it’s your escape hatch if a platform doesn’t work out.
Translation platforms accumulate valuable data over time: translations, translation memories, terminology, project history. In proprietary formats, this data is effectively trapped. Platform lock-in becomes real.
If your workflow generates XLIFF and your platform can export XLIFF, you maintain portability. Your translation investment isn’t hostage to a single vendor relationship.
This matters less when things are going well. It matters a great deal when things aren’t—when pricing changes, when features disappear, when a platform shuts down or gets acquired.
The standard worth knowing
XLIFF isn’t exciting technology. It’s plumbing—infrastructure that makes the visible parts of localization work smoothly. Understanding it gives you:
- Vocabulary to discuss file exchange precisely
- Ability to troubleshoot interchange problems
- Leverage in tool selection (don’t accept XLIFF limitations)
- Flexibility to evolve your workflow over time
For anyone involved in localization beyond the most casual level, basic XLIFF literacy pays ongoing dividends.
Language Ops generates XLIFF 1.2 and 2.0 from 80+ source formats and imports XLIFF from any compliant source. See the extraction workflow with your own files.
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