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LEP (.lep)

.lep file signature | application/octet-stream

LEP is a file format for Lepton-compressed JPEG images, developed by Dropbox and maintained as part of the open-source Lepton project. It is used to store photographs and other JPEG content in a smaller, lossless form for archival storage, synchronization, and bandwidth-efficient transfer. The format is associated with software compression/decompression workflows rather than direct editing, and it is generally considered safe when handled by current decoders.

Safe

Magic Bytes

Offset 0
CF 84 01

Sources: Wikipedia

Extension

.lep

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .lep files in Python

Python 
def is_lep(file_path: str) -> bool:
    """Check if file is a valid LEP by magic bytes."""
    signature = bytes([0xCF, 0x84, 0x01])
    with open(file_path, "rb") as f:
        return f.read(3) == signature

How to validate .lep files in Node.js

Node.js 
function isLEP(buffer: Buffer): boolean {
  const signature = Buffer.from([0xCF, 0x84, 0x01]);
  return buffer.subarray(0, 3).equals(signature);
}

How to validate .lep files in Go

Go 
func IsLEP(data []byte) bool {
    signature := []byte{0xCF, 0x84, 0x01}
    if len(data) < 3 {
        return false
    }
    return bytes.Equal(data[:3], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .lep file?

A .lep file is identified by the magic bytes CF 84 01 at byte offset 0. LEP is a file format for Lepton-compressed JPEG images, developed by Dropbox and maintained as part of the open-source Lepton project. It is used to store photographs and other JPEG content in a smaller, lossless form for archival storage, synchronization, and bandwidth-efficient transfer. The format is associated with software compression/decompression workflows rather than direct editing, and it is generally considered safe when handled by current decoders.

What are the magic bytes for .lep files?

The magic bytes for LEP files are CF 84 01 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .lep file?

To validate a .lep file, read the first bytes of the file and compare them against the known magic bytes (CF 84 01) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .lep files?

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

Is it safe to open .lep files?

LEP (.lep) 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.