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MS Windows journal file (.jnt)

.jnt file signature | application/octet-stream

Microsoft Windows Journal file (JNT) is a note-taking document format created by Microsoft and used by Windows Journal. It is primarily used for handwritten notes, sketches, annotations, and ink-based classroom or meeting records on compatible Windows systems. The format is associated with legacy tablet-era software and is now largely obsolete; like other document files, it should be opened cautiously if obtained from untrusted sources.

Safe

Magic Bytes

Offset 0
4E 42 2A 00

Sources: Gary Kessler

Extension

.jnt

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .jnt files in Python

Python 
def is_jnt(file_path: str) -> bool:
    """Check if file is a valid JNT by magic bytes."""
    signature = bytes([0x4E, 0x42, 0x2A, 0x00])
    with open(file_path, "rb") as f:
        return f.read(4) == signature

How to validate .jnt files in Node.js

Node.js 
function isJNT(buffer: Buffer): boolean {
  const signature = Buffer.from([0x4E, 0x42, 0x2A, 0x00]);
  return buffer.subarray(0, 4).equals(signature);
}

How to validate .jnt files in Go

Go 
func IsJNT(data []byte) bool {
    signature := []byte{0x4E, 0x42, 0x2A, 0x00}
    if len(data) < 4 {
        return false
    }
    return bytes.Equal(data[:4], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Related Formats

.jtp

Frequently Asked Questions

What is a .jnt file?

A .jnt file is a MS Windows journal file file. Microsoft Windows Journal file (JNT) is a note-taking document format created by Microsoft and used by Windows Journal. It is primarily used for handwritten notes, sketches, annotations, and ink-based classroom or meeting records on compatible Windows systems. The format is associated with legacy tablet-era software and is now largely obsolete; like other document files, it should be opened cautiously if obtained from untrusted sources.

What are the magic bytes for .jnt files?

The magic bytes for MS Windows journal file files are 4E 42 2A 00 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .jnt file?

To validate a .jnt file, read the first bytes of the file and compare them against the known magic bytes (4E 42 2A 00) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .jnt files?

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

Is it safe to open .jnt files?

MS Windows journal file (.jnt) 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.