Skip to content

M3A (.m3a)

.m3a file signature | audio/mpeg

M3A is an MPEG audio file format associated with the MPEG standards family, maintained by the ISO and IEC committees. It is used for storing compressed audio for playback in media players, archives, and distribution workflows that rely on MPEG-compatible sound streams. The format is generally safe, though files from untrusted sources should still be checked for corruption or malformed metadata, as with other legacy audio containers and streams.

Safe

Magic Bytes

Offset 0
FF F2

Sources: Apache Tika

All Known Signatures

12 signature variants are documented for .m3a files across multiple sources.

Hex Signature Offset Sources
FF F2 0 Apache Tika
FF F3 0 Apache Tika
FF F4 0 Apache Tika
FF F5 0 Apache Tika
FF F6 0 Apache Tika
FF F7 0 Apache Tika
FF FA 0 Apache Tika
FF FB 0 Apache Tika
FF FC 0 Apache Tika
FF FD 0 Apache Tika
FF E3 0 Apache Tika
49 44 33 0 Apache Tika

Extension

.m3a

MIME Type

audio/mpeg

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .m3a files in Python

Python 
def is_m3a(file_path: str) -> bool:
    """Check if file is a valid M3A by magic bytes."""
    signature = bytes([0xFF, 0xF2])
    with open(file_path, "rb") as f:
        return f.read(2) == signature

How to validate .m3a files in Node.js

Node.js 
function isM3A(buffer: Buffer): boolean {
  const signature = Buffer.from([0xFF, 0xF2]);
  return buffer.subarray(0, 2).equals(signature);
}

How to validate .m3a files in Go

Go 
func IsM3A(data []byte) bool {
    signature := []byte{0xFF, 0xF2}
    if len(data) < 2 {
        return false
    }
    return bytes.Equal(data[:2], signature)
}

API Endpoint

GET /api/v1/m3a
curl https://filesignature.org/api/v1/m3a

See the full API documentation for all endpoints and parameters.

Related Formats

.m2a .mp2 .mp2a .mpga .mp3

Frequently Asked Questions

What is a .m3a file?

A .m3a file is identified by the magic bytes FF F2 at byte offset 0. M3A is an MPEG audio file format associated with the MPEG standards family, maintained by the ISO and IEC committees. It is used for storing compressed audio for playback in media players, archives, and distribution workflows that rely on MPEG-compatible sound streams. The format is generally safe, though files from untrusted sources should still be checked for corruption or malformed metadata, as with other legacy audio containers and streams.

What are the magic bytes for .m3a files?

The magic bytes for M3A files are FF F2 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .m3a file?

To validate a .m3a file, read the first bytes of the file and compare them against the known magic bytes (FF F2) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .m3a files?

The primary MIME type for .m3a files is audio/mpeg.

Is it safe to open .m3a files?

M3A (.m3a) 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.