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AES Cryptfile format (.aes)

.aes file signature | application/octet-stream

AES Cryptfile format is an encrypted file format used by AES Crypt, developed and maintained by Packetizer, Inc. It is used to store and share files protected with password-based encryption on desktop and server systems, with support in common archive and encryption workflows. The format is designed for confidentiality, but security depends on strong passwords and careful handling of encrypted files; older files may use earlier version variants.

Safe

Magic Bytes

Offset 0
41 45 53

Sources: Gary Kessler

Extension

.aes

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .aes files in Python

Python 
def is_aes(file_path: str) -> bool:
    """Check if file is a valid AES by magic bytes."""
    signature = bytes([0x41, 0x45, 0x53])
    with open(file_path, "rb") as f:
        return f.read(3) == signature

How to validate .aes files in Node.js

Node.js 
function isAES(buffer: Buffer): boolean {
  const signature = Buffer.from([0x41, 0x45, 0x53]);
  return buffer.subarray(0, 3).equals(signature);
}

How to validate .aes files in Go

Go 
func IsAES(data []byte) bool {
    signature := []byte{0x41, 0x45, 0x53}
    if len(data) < 3 {
        return false
    }
    return bytes.Equal(data[:3], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .aes file?

A .aes file is a AES Cryptfile format file. AES Cryptfile format is an encrypted file format used by AES Crypt, developed and maintained by Packetizer, Inc. It is used to store and share files protected with password-based encryption on desktop and server systems, with support in common archive and encryption workflows. The format is designed for confidentiality, but security depends on strong passwords and careful handling of encrypted files; older files may use earlier version variants.

What are the magic bytes for .aes files?

The magic bytes for AES Cryptfile format files are 41 45 53 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .aes file?

To validate a .aes file, read the first bytes of the file and compare them against the known magic bytes (41 45 53) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .aes files?

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

Is it safe to open .aes files?

AES Cryptfile format (.aes) 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.