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JPGM (.jpgm)

.jpgm file signature | image/jpm

JPGM is a JPEG 2000 image format defined by the Joint Photographic Experts Group and standardized by ISO/IEC for storing bitmap images with advanced compression features. It is used for still images in archival systems, digital publishing, and specialized imaging workflows that require layered or high-fidelity image encoding. The format is less common than baseline JPEG, but it remains generally safe to open in modern viewers, with risks mainly limited to malformed files or decoder bugs.

Safe

Magic Bytes

Offset 0
00 00 00 0C 6A 50 20 20 0D 0A 87 0A

Sources: Apache Tika

Extension

.jpgm

MIME Type

image/jpm

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .jpgm files in Python

Python 
def is_jpgm(file_path: str) -> bool:
    """Check if file is a valid JPGM by magic bytes."""
    signature = bytes([0x00, 0x00, 0x00, 0x0C, 0x6A, 0x50, 0x20, 0x20, 0x0D, 0x0A, 0x87, 0x0A])
    with open(file_path, "rb") as f:
        return f.read(12) == signature

How to validate .jpgm files in Node.js

Node.js 
function isJPGM(buffer: Buffer): boolean {
  const signature = Buffer.from([0x00, 0x00, 0x00, 0x0C, 0x6A, 0x50, 0x20, 0x20, 0x0D, 0x0A, 0x87, 0x0A]);
  return buffer.subarray(0, 12).equals(signature);
}

How to validate .jpgm files in Go

Go 
func IsJPGM(data []byte) bool {
    signature := []byte{0x00, 0x00, 0x00, 0x0C, 0x6A, 0x50, 0x20, 0x20, 0x0D, 0x0A, 0x87, 0x0A}
    if len(data) < 12 {
        return false
    }
    return bytes.Equal(data[:12], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Related Formats

.jpm .jp2 .jpf .jxl .j2k .jpc

Frequently Asked Questions

What is a .jpgm file?

A .jpgm file is identified by the magic bytes 00 00 00 0C 6A 50 20 20 0D 0A 87 0A at byte offset 0. JPGM is a JPEG 2000 image format defined by the Joint Photographic Experts Group and standardized by ISO/IEC for storing bitmap images with advanced compression features. It is used for still images in archival systems, digital publishing, and specialized imaging workflows that require layered or high-fidelity image encoding. The format is less common than baseline JPEG, but it remains generally safe to open in modern viewers, with risks mainly limited to malformed files or decoder bugs.

What are the magic bytes for .jpgm files?

The magic bytes for JPGM files are 00 00 00 0C 6A 50 20 20 0D 0A 87 0A at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .jpgm file?

To validate a .jpgm file, read the first bytes of the file and compare them against the known magic bytes (00 00 00 0C 6A 50 20 20 0D 0A 87 0A) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .jpgm files?

The primary MIME type for .jpgm files is image/jpm.

Is it safe to open .jpgm files?

JPGM (.jpgm) 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.