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Skype localization data file (.mls)

.mls file signature | application/octet-stream

Milestones v2.1a project management and scheduling software(Also see "MILES" and "MV214" signatures)

Safe

Magic Bytes

Offset 0
4D 49 4C 45 53

Sources: Gary Kessler

All Known Signatures

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

Hex Signature Offset Sources
4D 49 4C 45 53 0 Gary Kessler
4D 4C 53 57 0 Gary Kessler
4D 56 32 31 34 0 Gary Kessler
4D 56 32 43 0 Gary Kessler

Extension

.mls

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .mls files in Python

Python
def is_mls(file_path: str) -> bool:
    """Check if file is a valid MLS by magic bytes."""
    signature = bytes([0x4D, 0x49, 0x4C, 0x45, 0x53])
    with open(file_path, "rb") as f:
        return f.read(5) == signature

How to validate .mls files in Node.js

Node.js
function isMLS(buffer: Buffer): boolean {
  const signature = Buffer.from([0x4D, 0x49, 0x4C, 0x45, 0x53]);
  return buffer.subarray(0, 5).equals(signature);
}

How to validate .mls files in Go

Go
func IsMLS(data []byte) bool {
    signature := []byte{0x4D, 0x49, 0x4C, 0x45, 0x53}
    if len(data) < 5 {
        return false
    }
    return bytes.Equal(data[:5], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .mls file?

A .mls file is a Skype localization data file file. Milestones v2.1a project management and scheduling software(Also see "MILES" and "MV214" signatures)

What are the magic bytes for .mls files?

The magic bytes for Skype localization data file files are 4D 49 4C 45 53 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .mls file?

To validate a .mls file, read the first bytes of the file and compare them against the known magic bytes (4D 49 4C 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 .mls files?

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

Is it safe to open .mls files?

Skype localization data file (.mls) 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.