MP4A (.mp4a)

.mp4a file signature | audio/mp4

Safe

Magic Bytes

Offset 4


              66 74 79 70 4D 34 41 20

Sources: Apache Tika

All Known Signatures

4 signature variants are documented for .mp4a files across multiple sources.

Hex Signature	Offset	Sources
66 74 79 70 4D 34 41 20	4	Apache Tika
66 74 79 70 4D 34 42 20	4	Apache Tika
66 74 79 70 46 34 41 20	4	Apache Tika
66 74 79 70 46 34 42 20	4	Apache Tika

Extension

.mp4a

MIME Type

audio/mp4

Byte Offset

Risk Level

Safe

Validation Code

How to validate .mp4a files in Python

Python

def is_mp4a(file_path: str) -> bool:
    """Check if file is a valid MP4A by magic bytes."""
    signature = bytes([0x66, 0x74, 0x79, 0x70, 0x4D, 0x34, 0x41, 0x20])
    with open(file_path, "rb") as f:
        return f.read(8) == signature

How to validate .mp4a files in Node.js

Node.js

function isMP4A(buffer: Buffer): boolean {
  const signature = Buffer.from([0x66, 0x74, 0x79, 0x70, 0x4D, 0x34, 0x41, 0x20]);
  return buffer.subarray(0, 8).equals(signature);
}

How to validate .mp4a files in Go

func IsMP4A(data []byte) bool {
    signature := []byte{0x66, 0x74, 0x79, 0x70, 0x4D, 0x34, 0x41, 0x20}
    if len(data) < 8 {
        return false
    }
    return bytes.Equal(data[:8], signature)
}

API Endpoint

GET /api/v1/mp4a


              curl https://filesignature.org/api/v1/mp4a

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .mp4a file?

A .mp4a file is a MP4A file.

What are the magic bytes for .mp4a files?

The magic bytes for MP4A files are 66 74 79 70 4D 34 41 20 at byte offset 4. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .mp4a file?

To validate a .mp4a file, read the first bytes of the file and compare them against the known magic bytes (66 74 79 70 4D 34 41 20) at offset 4. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .mp4a files?

The primary MIME type for .mp4a files is audio/mp4.

Is it safe to open .mp4a files?

MP4A (.mp4a) 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.