What is the CDT file format?
A .cdt file is a CorelDRAW vector graphics template - structurally identical to a .cdr drawing file but saved with the .cdt extension so CorelDRAW opens it as a template, creating a new untitled document rather than editing the original. Templates store page size and orientation, colour palettes, paragraph and graphic styles, ruler/grid/guideline settings, and any pre-placed vector artwork or placeholder objects.
CorelDRAW has used two underlying container formats. Versions 1 through 13 (1989-2001) used a RIFF binary container; files begin with the bytes RIFF and the chunk type CDT plus a version code. From CorelDRAW X4 (version 14, 2008) onwards the container switched to a ZIP archive with DEFLATE compression, and files begin with the PK signature. Both generations are supported by current CorelDRAW releases.
The newer .cdrt extension (introduced around CorelDRAW 14-16) is the designated successor for ZIP-based templates; older .cdt files from earlier versions remain widely distributed and fully supported.
Third-party support is limited: Inkscape and LibreOffice Draw can import .cdt via the libcdr library (the same path used for .cdr files), with good fidelity for simple graphics but potential issues with CorelDRAW-specific effects, fonts, and colour spaces. Adobe Illustrator does not natively open .cdt files.
Security & safety
RISK: MEDIUMCDT files are vector data, not executable. The risk is identical to CDR: searches for free 'CDT opener' or 'CDT viewer' may surface low-trust downloads. Use Inkscape (inkscape.org) or LibreOffice (libreoffice.org) rather than no-name viewer executables. ZIP-based CDT files (CorelDRAW X4+) are archives and could embed files, but this is not an active attack vector.
Format details
in a nutshellFULL NAMECorelDRAW Templateaka CDT template, CorelDRAW image template
DEVELOPERCorel Corporationsince 1989 (CorelDRAW 1.0; .cdt template variant alongside .cdr)
CATEGORYVector Image Files
MIME TYPEapplication/x-coreldraw
TYPEProprietary vector graphics template (RIFF-based or ZIP-based, same as CDR)
This extension is also used by…
- C++ Development Tools project file (Eclipse CDT) - Eclipse IDE's C/C++ Development Tools uses .cdt for project configuration files - unrelated to CorelDRAW.
- Commodore 64 tape image - C64 emulators (e.g. VICE) use .cdt for Commodore 64 cassette tape images - unrelated to graphics.
MAGIC BYTES · FILE SIGNATURE
OFFSET
00010203
HEX
52494646
ASCII
RIFF
CDT and CDR share the same binary format - older files use RIFF container (bytes 0-3 'RIFF', bytes 8-11 'CDT' + version); CorelDRAW X4 (v14, 2008) and later use ZIP container (starts with 'PK'). From CorelDRAW 14-16+ templates may use the newer .cdrt extension.
Programs that open CDT files
Windows3 apps
CorelDRAW
Paid Double-click the .cdt or File > New From Template - CorelDRAW opens a copy. Full support for all versions. Free trial available. 
Inkscape
Open-source File > Open the .cdt (imported via libcdr). Partial support - works on simpler/older files; recent CorelDRAW effects may not render correctly. 
LibreOffice Draw
Open-source Open the .cdt to view/export (uses libcdr). Good for viewing and converting to PDF/SVG/PNG; not a precise CorelDRAW editor. 
macOS2 apps
CorelDRAW
Paid File > New From Template - opens a new document from the .cdt. CorelDRAW returned to macOS. 
Linux2 apps
Technical details
deep spec| Encoding | Binary |
| Byte order | Little-endian (RIFF structure); little-endian internally in ZIP era as well |
| Container | RIFF binary container (CorelDRAW 1-13, 1989-2001); ZIP archive (CorelDRAW X4 / v14+, 2008 onwards) |
| Magic bytes | 52 49 46 46 (RIFF) at offset 0 for v1-13; 50 4B 03 04 (PK) at offset 0 for v14+ ZIP-based files |
| Compression | None in RIFF era; DEFLATE per ZIP entry in v14+ era |
| Typical size | 20 KB - 50 MB (simple logo templates to multi-page document templates with embedded artwork) |
| Internal format version | RIFF chunk type CDT plus version code (v1-13); XML and RIFF streams inside ZIP package (v14+) |
| Template behaviour | CorelDRAW opens .cdt as a new untitled document copy; the original template is never modified |
| Relation to CDR | Structurally identical to .cdr drawing files; only the extension and CorelDRAW's open-as-template behaviour differ |
| Successor format | .cdrt - CorelDRAW Template for ZIP-based format (CorelDRAW 14-16+); .cdt remains fully supported |
| Third-party import | Inkscape and LibreOffice Draw via libcdr library; fidelity limited for CorelDRAW-specific effects, fonts, and colour spaces |
| Checksum/integrity | None in RIFF era; ZIP CRC-32 per entry in v14+ era |
| Platform | Windows (full support); macOS via CorelDRAW for Mac (version 19/2019 and later) |
| Released | 1989 (CorelDRAW 1.0; .cdt template variant alongside .cdr) |
| Latest version | CorelDRAW 2024 (v26) - newer versions use .cdrt extension |
| Specification | www.coreldraw.com |
CDT conversions
Possible
.CDT .JPEGGUIDE
Yes. Open the CDT in CorelDRAW, Inkscape or LibreOffice Draw and export it as JPEG.
How to convert
.CDT .PDFGUIDE
Yes, you can convert a CDT to PDF by opening it in CorelDRAW, Inkscape or LibreOffice Draw and exporting to…
How to convert
.CDT .PNGGUIDE
Yes. Open the .cdt in CorelDRAW, Inkscape or LibreOffice Draw and export it to PNG at the resolution you need.
How to convert
.CDT .AIGUIDE
Yes - the fastest route is to open the CDT in CorelDRAW and export straight to .ai, though going through PDF…
How to convert
.CDT .EPSGUIDE
Yes, you can convert a CDT to EPS by opening the CorelDRAW Template in CorelDRAW or Inkscape and exporting to…
How to convert
.CDT .SVGGUIDE
Yes, you can convert a CDT to SVG, and the fastest free way is to open the .cdt in Inkscape and use Save As >…
How to convert
.CDT .CDRGUIDE
Yes, you can convert CDT to CDR in seconds by opening the template in CorelDRAW and choosing Save As CDR.
How to convert
.CDT .PLTGUIDE
Yes, you can convert CDT to PLT, and the fastest way is to open the template in CorelDRAW and use File >…
How to convert
.CDT .DWGGUIDE
Yes, you can convert a CDT to DWG, and the fastest way is to open the template in CorelDRAW and use File >…
How to convert
Community Q&A
asked by users
L
Frequently asked questions
How do I open a CDT file without CorelDRAW?
Use Inkscape or LibreOffice Draw - both are free and use the libcdr library to import CDT/CDR files. Support is partial for complex files; simpler templates open well.
What is the difference between CDT and CDR?
CDT is a template - CorelDRAW opens it by creating a new copy rather than editing the original. CDR is a regular drawing. Structurally they use the same binary format.
What is the difference between CDT and CDRT?
.cdrt is the newer CorelDRAW template format introduced around CorelDRAW 14-16+; .cdt is the older format. Newer CorelDRAW versions default to .cdrt. Older .cdt files may not open in the very latest CorelDRAW.
Can I convert a CDT to PDF?
Yes - open it in CorelDRAW (best fidelity), Inkscape or LibreOffice Draw and export or save as PDF.
Can Inkscape open CDT files?
Partially. Inkscape uses the libcdr library to import CDT/CDR; it works well on simpler/older files but may fail or render incorrectly on files using advanced CorelDRAW effects.
References
1CorelDRAW - official product pagewww.coreldraw.com
2Inkscape - official siteinkscape.org
