Detect and validate
Open TLC checks content as well as the filename, applies archive and XML limits, and selects a dedicated format adapter.
Format-aware by design
How files move through Open TLC
A DOCX document, a PO catalog and an EPUB publication do not have the same structure. Open TLC routes each supported file through an adapter with its own extraction, validation and export behavior.
Extract and translate
The adapter exposes translatable content as segments while protecting inline codes, placeholders and structural metadata.
Verify and export
Format-specific checks run before the translated document or portable project file is generated.
Translation safeguards: Inline codes and placeholders
remain protected, split and join operations retain their segment lineage,
and structured imports can offer format-specific extraction options.
Auxiliary resource safety: INF imports only selected localized
Strings sections, REG imports only typed string-bearing values, and FreeMind
imports node labels and visible rich content. Setup directives, registry
keys and binary values, node IDs, links, hooks, scripts and unknown XML
remain inert and unchanged. REG files are downloaded as files and are never
applied to the operating system.
Outlook message safety: MSG files are verified as compound
MAPI items and read locally. Sender and recipients are context; subject,
the selected plain/HTML body and optional attachment names are editable.
Attachments and unknown properties remain opaque, nested messages are rejected,
and HTML is never rendered or allowed to fetch external content. Unchanged
projects retain the original MSG; edited delivery uses safe EML.
Visio support: VSDX-family OPC packages and standalone
Visio XML retain their drawing, stencil, or template family while only
localized XML values change. Geometry, formulas, relationships, macros,
embedded objects, images, and unknown resources remain protected. Legacy
compound binaries retain exact bytes when unchanged and use an explicit
VDX delivery after translation.
Adobe and Quark support: IDML, ICML, INX, FrameMaker MIF/MIF2
and XPress Tags use structure-aware text round trips. Photoshop PSD reads
only validated text-layer descriptors; an unchanged project retains the
exact PSD, while translated delivery is a safe SVG text-layer conversion.
Specialist XML and SGML: ITS rules, MULIX, Author-it,
MadCap, TYPO3 and SpreadsheetML use vocabulary-specific extraction and
protected-content rules. DITA BOOKMAP retains its native DITA family. Constrained
SGML accepts only validated XML-compatible markup with a safe fixed doctype;
entities and network schemas are never resolved.
Source document support
Formats you can bring into the editor
The groups below cover native round-trip adapters and deliberately limited parsers. Exact behavior depends on the selected format and is validated before export. The browser-based adapters work consistently across operating systems.
Office, web and text
- DOCX
- XLSX
- PPTX
- Legacy Office + XLSB
- RTF
- OpenDocument documents, templates, masters + formulas
- HTML, server pages and HTML Help
- TXT
- CSV/TSV
- PDF → translated PDF
Software localization
- JSON families
- YAML 1.2
- GNU gettext PO/POT
- Android resources
- Apple localization
- Java/Mozilla properties
- .NET RESX
- Qt Linguist TS
- Qt QML source
- INI/desktop/lang
- PHP localization arrays
- Windows RC
- Windows INF/REG + FreeMind MM
- Outlook MSG → safe EML
Publishing and technical authoring
- Markdown/AsciiDoc
- EPUB 2/3
- SVG
- DITA/DITAMAP/BOOKMAP
- DocBook 4/5
- Adobe IDML/ICML/INX
- TeX/LaTeX
- TTML/DFXP
- Adobe FrameMaker MIF / MIF2
- Microsoft Visio drawings, stencils and templates
- QuarkXPress Tags
- Photoshop PSD text layers → SVG
- ITS, MULIX, Author-it, MadCap, TYPO3, SpreadsheetML + safe SGML
- XML + ITS 2.0
Bilingual exchange and packages
- TTX / ITD / TXML / Workbench bilingual
- CAT handoff and return packages
- Manifest-driven ZIP projects
- XLIFF 1.2 / 2.0 / 2.1, SDLXLIFF, memoQ XLIFF, Phrase MXLIFF, WorldServer WsXLIFF, WPML and XLIFF:doc
- TMX 1.4b translation memories and TBX terminology
Subtitles and local media
- SRT/WebVTT/SBV/ASS/SSA/Spruce STL subtitles
- PNG/JPEG/TIFF/BMP/DIB/GIF local OCR → bilingual HTML
- Audio/video local transcription → WebVTT
Office package support: DOCX, XLSX and PPTX families use
platform-independent browser adapters with automated import, edit, export,
validation and re-import coverage. OpenDocument documents, templates, master
documents and formulas retain their exact package family; scripts and embedded
objects remain inert, unedited resources.
Industry exchange
CAT projects, memories and terminology
Open TLC imports and exports standard XLIFF 1.2, 2.0 and 2.1 projects. SDLXLIFF, MQXLIFF/MQXLF, Phrase MXLIFF, WorldServer WsXLIFF, WPML, XLIFF:doc and recognized CMS/e-learning variants use a dedicated same-profile export that retains vendor namespaces, workflow state, inline codes, skeletons and unknown extensions. TTX, ITD, TXML and Workbench bilingual files use structural detection and protected target-only writers. The `.xlif` alias is accepted alongside `.xlf` and `.xliff`.
- TMX 1.4bTranslation-memory exchange
- TBX Core / MinTerminology exchange
- SRX 2.0Segmentation-rule exchange
- XLIFF 1.2–2.1Bilingual project exchange
- Legacy bilingual CATTTX, ITD, TXML and Workbench files
- CAT return packagesTrados, WorldServer, memoQ, Transit, TIPP and COTI handoff
Support boundaries
Some files need a safer, narrower workflow
The interface labels these capabilities instead of implying that every file can make a lossless browser-only round trip.
Born-digital text is mapped to its original page and bounding box. Export locally renders each source page, replaces mapped text areas, and writes a new flattened PDF with a searchable target-language text layer; an accessible bilingual HTML review remains available. Complex fonts, transparent artwork and scanned pages can still need a visual review.
Trados, WorldServer, memoQ, Transit, TIPP and COTI packages are inspected safely, their validated bilingual members are updated, and every other entry is retained when the return container is rebuilt.
DOC/DOT/BAK, XLS/XLT/XLSB, PPT/PPS/POT and RTF are inspected and imported locally. Unchanged files retain their exact binary family; translated spreadsheet variants use an explicit XLSX/XLSM conversion; Word variants export to DOCX and PowerPoint binary variants export to HTML as explicit conversions. Standalone SLDX slides retain their OOXML package and unknown resources.
TTX, ITD, TXML, XLIFF:doc and RTF/DOCX-based Workbench files retain delimiters, inline tags, IDs, states, hidden styles and unknown content. Edited binary OLE Workbench DOC/BAK files use an explicit bilingual RTF delivery because safely rewriting arbitrary Word binary streams in the browser is not defined.
VSD, VSS, VDW and legacy compound variants are inspected locally without executing macros, formulas, links, or embedded objects. Exact identity exports keep the original bytes; translated delivery uses VDX. VSDX, VSDM, VSSX, VSSM, VSTX, VSTM, VDX, VSX and VTX retain their native family.
PSD files are accepted only after their 8BPS header and layer structure validate. Pixel data, linked files, smart objects, effects, annotations and unknown resources are never executed and remain in the retained original. Unchanged output is the exact PSD; translated output is SVG because browser-side PSD text rewriting cannot preserve every Photoshop feature safely.
Generic ZIP import is available only for packages with a validated opentlc-project.json manifest and safe member paths.
PNG, JPEG, TIFF, BMP, DIB and GIF images are read with local OCR; audio/video is transcribed with a local Whisper model. Model files may be downloaded and cached by the browser, but source media is not uploaded and no provider consent is needed.
Privacy and ownership
Projects live in your browser
Open TLC stores project data in IndexedDB on the current device and browser profile. The application does not send project content to an Open TLC storage server.
Keep regular backups
Browser data can still be lost through site-data clearing, profile changes, device failure or browser maintenance. Export project files regularly and store them somewhere you control.
To move a project to another browser or device, export it on the first device and import that file on the second.
Portable project saves
Open TLC JSON and XLIFF
The versioned Open TLC JSON format keeps application-specific project state in a readable structure. Standard XLIFF 1.2, 2.0 and 2.1 exports provide interoperable bilingual project files for compatible CAT tools. Imported vendor XLIFF is returned through a separate same-profile writer, so generic conversion cannot silently discard its proprietary workflow metadata.
Project-save formats are separate from translated source-document exports: an XLIFF save preserves a bilingual project, while a DOCX, PO, EPUB or other source export rebuilds that source format.
View the Open TLC project data structure
Example Project Name (ID #1)
Source Language: English (en)
Target Language: German (de)
Created on: 11/2/2024
Type: Text
Translation Segments
| # | Source Segment | Target Segment | Checked |
|---|---|---|---|
| 1 | Segment 1 | Translated Segment 1 | |
| 2 | Segment 2 |
Open source contribution
Real files make format support better
Developers, translators and technical writers can contribute code, sanitized fixtures, interoperability results, documentation and issue reports.