Font file (.fon)
.fon file signature | application/octet-stream
DOS MZ executableand its descendants (includingNEandPE)
Magic Bytes
Offset 0
4D 5A
Sources: Wikipedia, Gary Kessler
Extension
.fon
MIME Type
application/octet-stream
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .fon files in Python
def is_fon(file_path: str) -> bool:
"""Check if file is a valid FON by magic bytes."""
signature = bytes([0x4D, 0x5A])
with open(file_path, "rb") as f:
return f.read(2) == signatureHow to validate .fon files in Node.js
function isFON(buffer: Buffer): boolean {
const signature = Buffer.from([0x4D, 0x5A]);
return buffer.subarray(0, 2).equals(signature);
}How to validate .fon files in Go
func IsFON(data []byte) bool {
signature := []byte{0x4D, 0x5A}
if len(data) < 2 {
return false
}
return bytes.Equal(data[:2], signature)
}API Endpoint
/api/v1/fon
curl https://filesignature.org/api/v1/fon
See the full API documentation for all endpoints and parameters.
Frequently Asked Questions
What is a .fon file?
A .fon file is a Font file file. DOS MZ executableand its descendants (includingNEandPE)
What are the magic bytes for .fon files?
The magic bytes for Font file files are 4D 5A at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .fon file?
To validate a .fon file, read the first bytes of the file and compare them against the known magic bytes (4D 5A) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .fon files?
There is no officially registered MIME type for .fon files. Systems typically use application/octet-stream as a generic fallback when handling this format.
Is it safe to open .fon files?
Font file (.fon) 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.