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Matroska stream file (.mkv)

.mkv file signature | video/x-matroska

Matroskamedia container, includingWebM

Safe

Magic Bytes

Offset 0
1A 45 DF A3

Sources: Wikipedia, Gary Kessler

All Known Signatures

2 signature variants are documented for .mkv files across multiple sources.

Hex Signature Offset Sources
1A 45 DF A3 0 Wikipedia, Gary Kessler
1A 45 DF A3 93 42 82 88 6D 61 74 72 6F 73 6B 61 0 Apache Tika

Extension

.mkv

MIME Type

video/x-matroska

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .mkv files in Python

Python
def is_mkv(file_path: str) -> bool:
    """Check if file is a valid MKV by magic bytes."""
    signature = bytes([0x1A, 0x45, 0xDF, 0xA3])
    with open(file_path, "rb") as f:
        return f.read(4) == signature

How to validate .mkv files in Node.js

Node.js
function isMKV(buffer: Buffer): boolean {
  const signature = Buffer.from([0x1A, 0x45, 0xDF, 0xA3]);
  return buffer.subarray(0, 4).equals(signature);
}

How to validate .mkv files in Go

Go
func IsMKV(data []byte) bool {
    signature := []byte{0x1A, 0x45, 0xDF, 0xA3}
    if len(data) < 4 {
        return false
    }
    return bytes.Equal(data[:4], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .mkv file?

A .mkv file is a Matroska stream file file. Matroskamedia container, includingWebM

What are the magic bytes for .mkv files?

The magic bytes for Matroska stream file files are 1A 45 DF A3 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .mkv file?

To validate a .mkv file, read the first bytes of the file and compare them against the known magic bytes (1A 45 DF A3) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .mkv files?

The primary MIME type for .mkv files is video/x-matroska.

Is it safe to open .mkv files?

Matroska stream file (.mkv) 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.