MHTML (.mhtml)
.mhtml file signature | multipart/related
Magic Bytes
Offset 0
4D 49 4D 45 2D 56 65 72 73 69 6F 6E 3A 20 31 2E 30
Sources: Apache Tika
Extension
.mhtml
MIME Type
multipart/related
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .mhtml files in Python
def is_mhtml(file_path: str) -> bool:
"""Check if file is a valid MHTML by magic bytes."""
signature = bytes([0x4D, 0x49, 0x4D, 0x45, 0x2D, 0x56, 0x65, 0x72, 0x73, 0x69, 0x6F, 0x6E, 0x3A, 0x20, 0x31, 0x2E, 0x30])
with open(file_path, "rb") as f:
return f.read(17) == signatureHow to validate .mhtml files in Node.js
function isMHTML(buffer: Buffer): boolean {
const signature = Buffer.from([0x4D, 0x49, 0x4D, 0x45, 0x2D, 0x56, 0x65, 0x72, 0x73, 0x69, 0x6F, 0x6E, 0x3A, 0x20, 0x31, 0x2E, 0x30]);
return buffer.subarray(0, 17).equals(signature);
}How to validate .mhtml files in Go
func IsMHTML(data []byte) bool {
signature := []byte{0x4D, 0x49, 0x4D, 0x45, 0x2D, 0x56, 0x65, 0x72, 0x73, 0x69, 0x6F, 0x6E, 0x3A, 0x20, 0x31, 0x2E, 0x30}
if len(data) < 17 {
return false
}
return bytes.Equal(data[:17], signature)
}API Endpoint
/api/v1/mhtml
curl https://filesignature.org/api/v1/mhtml
See the full API documentation for all endpoints and parameters.
Frequently Asked Questions
What is a .mhtml file?
A .mhtml file is a MHTML file.
What are the magic bytes for .mhtml files?
The magic bytes for MHTML files are 4D 49 4D 45 2D 56 65 72 73 69 6F 6E 3A 20 31 2E 30 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .mhtml file?
To validate a .mhtml file, read the first bytes of the file and compare them against the known magic bytes (4D 49 4D 45 2D 56 65 72 73 69 6F 6E 3A 20 31 2E 30) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .mhtml files?
The primary MIME type for .mhtml files is multipart/related.
Is it safe to open .mhtml files?
MHTML (.mhtml) 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.