Web Open Font Format
application/octet-stream
Magic Bytes
Offset: 0
77 4F 46 46
The Web Open Font Format (WOFF) is a font packaging standard developed by Mozilla, Microsoft, and Opera, currently maintained by the World Wide Web Consortium. It wraps TrueType and OpenType fonts in a compressed container to facilitate the efficient delivery of custom typography for web browsers and digital interfaces. Although largely superseded by WOFF2, this format remains a secure, stable choice for broad compatibility across legacy systems without introducing significant security vulnerabilities to the end user.
Validation Code
How to validate .woff files in Python
Python
def is_woff(file_path: str) -> bool:
"""Check if file is a valid WOFF by magic bytes."""
signature = bytes([0x77, 0x4F, 0x46, 0x46])
with open(file_path, "rb") as f:
return f.read(4) == signatureHow to validate .woff files in Node.js
Node.js
function isWOFF(buffer: Buffer): boolean {
const signature = Buffer.from([0x77, 0x4F, 0x46, 0x46]);
return buffer.subarray(0, 4).equals(signature);
}
Go
func IsWOFF(data []byte) bool {
signature := []byte{0x77, 0x4F, 0x46, 0x46}
if len(data) < 4 {
return false
}
return bytes.Equal(data[:4], signature)
}API Endpoint
GET
/api/v1/woff
curl https://filesignature.org/api/v1/woff