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QT (.qt)

.qt file signature | video/quicktime

QuickTime (QT) is a multimedia file format developed by Apple for storing video, audio, and time-based media. It is used for playback and editing in media applications, especially in older QuickTime-compatible players and authoring tools. The format is largely legacy, and while generally safe as a media container, files from untrusted sources should still be opened with up-to-date software and reviewed cautiously.

Safe

Magic Bytes

Offset 4
6D 6F 6F 76 00

Sources: Apache Tika

All Known Signatures

7 signature variants are documented for .qt files across multiple sources.

Hex Signature Offset Sources
6D 6F 6F 76 00 4 Apache Tika
6D 64 61 74 00 4 Apache Tika
66 72 65 65 00 4 Apache Tika
73 6B 69 70 00 4 Apache Tika
70 6E 6F 74 00 4 Apache Tika
66 74 79 70 4 Apache Tika
00 00 00 08 77 69 64 65 0 Apache Tika

Extension

.qt

MIME Type

video/quicktime

Byte Offset

4

Risk Level

Safe

Validation Code

How to validate .qt files in Python

Python
def is_qt(file_path: str) -> bool:
    """Check if file is a valid QT by magic bytes at offset 4."""
    signature = bytes([0x6D, 0x6F, 0x6F, 0x76, 0x00])
    with open(file_path, "rb") as f:
        f.seek(4)
        return f.read(5) == signature

How to validate .qt files in Node.js

Node.js
function isQT(buffer: Buffer): boolean {
  const signature = Buffer.from([0x6D, 0x6F, 0x6F, 0x76, 0x00]);
  if (buffer.length < 9) return false;
  return buffer.subarray(4, 9).equals(signature);
}

How to validate .qt files in Go

Go
func IsQT(data []byte) bool {
    signature := []byte{0x6D, 0x6F, 0x6F, 0x76, 0x00}
    if len(data) < 9 {
        return false
    }
    return bytes.Equal(data[4:9], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Related Formats

Frequently Asked Questions

What is a .qt file?

A .qt file is identified by the magic bytes 6D 6F 6F 76 00 at byte offset 4. QuickTime (QT) is a multimedia file format developed by Apple for storing video, audio, and time-based media. It is used for playback and editing in media applications, especially in older QuickTime-compatible players and authoring tools. The format is largely legacy, and while generally safe as a media container, files from untrusted sources should still be opened with up-to-date software and reviewed cautiously.

What are the magic bytes for .qt files?

The magic bytes for QT files are 6D 6F 6F 76 00 at byte offset 4. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .qt file?

To validate a .qt file, read the first bytes of the file and compare them against the known magic bytes (6D 6F 6F 76 00) at offset 4. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .qt files?

The primary MIME type for .qt files is video/quicktime.

Is it safe to open .qt files?

QT (.qt) 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.