What is the CPT file format?
.CPT is a file created by Corel PHOTO-PAINT, the bitmap editing application included in the CorelDRAW Graphics Suite. .cpt files store bitmap image data much like .BMP files do, but go considerably further: a .cpt document can contain multiple objects (layers), masks, alpha channels, transparency settings, embedded objects and effects - and in some versions also the project's undo history.
Exporting .cpt files
Full editing of .cpt files is best done within Corel PHOTO-PAINT itself; third-party tools such as XnView MP can open .cpt files for viewing but may not preserve all layer and effect data. The file can easily be exported to many popular image formats - .JPG, .PNG, .gif or .bmp - using the export feature from the PHOTO-PAINT menu. For maximum compatibility, flattening and exporting to .TIF or .png before sharing is recommended.
Color modes supported in .cpt files
The .cpt format supports the following color modes:
- Black and white (1-bit)
- Greyscale
- RGB (24-bit; up to 48-bit color in later versions)
- CMYK
- LAB
Security & safety
RISK: MEDIUMA .cpt is image data, not executable, so the file itself poses little direct risk. The real hazard mirrors the CDR ecosystem: searches for free "CPT viewer/opener" lead to abandoned, ad-laden or PUP-bundled downloads. Stick to Corel PHOTO-PAINT or XnView (from xnview.com), or a reputable converter, and avoid no-name "CPT Viewer" executables. Note also that .cpt is reused by encryption tools (CryptaPix) - an encrypted .cpt won't open as an image and shouldn't be forced.
Format details
in a nutshell- Encrypted file (CryptaPix / PGP-style) - Some encryption tools (e.g. CryptaPix) save .cpt as an encrypted image/data file - not a Corel bitmap.
- FileWrangler / generic compressed-template files - A few legacy utilities used .cpt for compressed or template data; niche and unrelated.
Programs that open CPT files
Windows3 apps
CorelDRAW
Paid Import the .cpt (PHOTO-PAINT image) into a CorelDRAW document. Same suite as PHOTO-PAINT. 
Corel PHOTO-PAINT (CorelDRAW Graphics Suite)
Paid Open the .cpt directly - the only app that reads every CPT version with full layers/objects. Free trial; otherwise subscription/one-off licence. 
XnView MP
Free Open the .cpt to view and convert it (handles many CPT files; flattened, not full layer editing). Free for personal use. 
macOS2 apps
Corel PHOTO-PAINT (CorelDRAW Graphics Suite)
Paid Open natively (CorelDRAW returned to macOS). Free trial available. 
Linux1 app
XnView MP
Free Run the Linux build and open the .cpt for viewing/conversion (no native Corel on Linux). Technical details
deep spec| MIME type | application/x-corelphotopaint |
| Magic bytes | ASCII string "CPT FILE" at byte offset 0 (CPT7/8/9); TIFF byte-order marker for the legacy CPT6 format |
| Byte order | Little-endian (CPT7+); CPT6 inherits the TIFF byte-order marker (II for little-endian, MM for big-endian) |
| Container | Proprietary chunked layout (CPT7/8/9); CPT6 uses a TIFF-based container |
| Compression | Lossless RLE/packbits-style internal compression (CPT7+); CPT6 uses standard TIFF compression schemes |
| Internal format versions | Four generations: CPT6 (TIFF-like, pre-v7.0), CPT7 (1997), CPT8 and CPT9 |
| Color depth | 1-bit (B&W), 8-bit grayscale, 24-bit RGB, 32-bit RGBA, 32-bit CMYK; up to 48-bit per channel in later versions |
| Color modes | Black & white, grayscale, RGB, CMYK, LAB |
| Layer model | Multiple independent objects (layers) composited over a background image |
| Mask and alpha support | Per-object masks and alpha channels, plus a global image mask |
| Typical file size | 1 MB to several hundred MB, depending on resolution and object count |
| Platform support | Windows (primary); macOS supported in older versions and recent CorelDRAW Graphics Suite releases |
| Third-party compatibility | XnView MP can open .cpt files for viewing; full round-trip editing requires Corel PHOTO-PAINT |
| Proprietary status | Undocumented proprietary format (CPT7 through CPT9); no public specification exists |
| Released | Corel PHOTO-PAINT (early 1990s); proprietary CPT7 since version 7.0 (1997) |
| Latest version | CPT9-era format (used by recent CorelDRAW Graphics Suite releases) |
| Specification | www.coreldraw.com |
CPT conversions
Community Q&A
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