MOBI (.mobi)
.mobi file signature | application/x-mobipocket-ebook
Magic Bytes
Offset 0
42 4F 4F 4B 4D 4F 42 49
Sources: Apache Tika
Extension
.mobi
MIME Type
application/x-mobipocket-ebook
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .mobi files in Python
def is_mobi(file_path: str) -> bool:
"""Check if file is a valid MOBI by magic bytes."""
signature = bytes([0x42, 0x4F, 0x4F, 0x4B, 0x4D, 0x4F, 0x42, 0x49])
with open(file_path, "rb") as f:
return f.read(8) == signatureHow to validate .mobi files in Node.js
function isMOBI(buffer: Buffer): boolean {
const signature = Buffer.from([0x42, 0x4F, 0x4F, 0x4B, 0x4D, 0x4F, 0x42, 0x49]);
return buffer.subarray(0, 8).equals(signature);
}How to validate .mobi files in Go
func IsMOBI(data []byte) bool {
signature := []byte{0x42, 0x4F, 0x4F, 0x4B, 0x4D, 0x4F, 0x42, 0x49}
if len(data) < 8 {
return false
}
return bytes.Equal(data[:8], signature)
}API Endpoint
/api/v1/mobi
curl https://filesignature.org/api/v1/mobi
See the full API documentation for all endpoints and parameters.
Frequently Asked Questions
What is a .mobi file?
A .mobi file is a MOBI file.
What are the magic bytes for .mobi files?
The magic bytes for MOBI files are 42 4F 4F 4B 4D 4F 42 49 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .mobi file?
To validate a .mobi file, read the first bytes of the file and compare them against the known magic bytes (42 4F 4F 4B 4D 4F 42 49) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .mobi files?
The primary MIME type for .mobi files is application/x-mobipocket-ebook.
Is it safe to open .mobi files?
MOBI (.mobi) 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.