Skip to content

Corel Photopaint file (.cpt)

.cpt file signature | application/octet-stream

Corel Photopaint file

Safe

Magic Bytes

Offset 0
43 50 54 37 46 49 4C 45

Sources: Gary Kessler

All Known Signatures

2 signature variants are documented for .cpt files across multiple sources.

Hex Signature Offset Sources
43 50 54 37 46 49 4C 45 0 Gary Kessler
43 50 54 46 49 4C 45 0 Gary Kessler

Extension

.cpt

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .cpt files in Python

Python 
def is_cpt(file_path: str) -> bool:
    """Check if file is a valid CPT by magic bytes."""
    signature = bytes([0x43, 0x50, 0x54, 0x37, 0x46, 0x49, 0x4C, 0x45])
    with open(file_path, "rb") as f:
        return f.read(8) == signature

How to validate .cpt files in Node.js

Node.js 
function isCPT(buffer: Buffer): boolean {
  const signature = Buffer.from([0x43, 0x50, 0x54, 0x37, 0x46, 0x49, 0x4C, 0x45]);
  return buffer.subarray(0, 8).equals(signature);
}

How to validate .cpt files in Go

Go 
func IsCPT(data []byte) bool {
    signature := []byte{0x43, 0x50, 0x54, 0x37, 0x46, 0x49, 0x4C, 0x45}
    if len(data) < 8 {
        return false
    }
    return bytes.Equal(data[:8], signature)
}

API Endpoint

GET /api/v1/cpt
curl https://filesignature.org/api/v1/cpt

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .cpt file?

A .cpt file is a Corel Photopaint file file. Corel Photopaint file

What are the magic bytes for .cpt files?

The magic bytes for Corel Photopaint file files are 43 50 54 37 46 49 4C 45 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .cpt file?

To validate a .cpt file, read the first bytes of the file and compare them against the known magic bytes (43 50 54 37 46 49 4C 45) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .cpt files?

There is no officially registered MIME type for .cpt files. Systems typically use application/octet-stream as a generic fallback when handling this format.

Is it safe to open .cpt files?

Corel Photopaint file (.cpt) files are generally safe to open. They are classified as low risk because they primarily contain data rather than executable code. However, always ensure files come from a trusted source.