Web Open Font Format (.woff)
.woff file signature | application/octet-stream
WOFF File Format 1.0[64]
Magic Bytes
Offset 0
77 4F 46 46
Sources: Wikipedia, Gary Kessler
Extension
.woff
MIME Type
application/octet-stream
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .woff files in 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
function isWOFF(buffer: Buffer): boolean {
const signature = Buffer.from([0x77, 0x4F, 0x46, 0x46]);
return buffer.subarray(0, 4).equals(signature);
}How to validate .woff files in 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
/api/v1/woff
curl https://filesignature.org/api/v1/woff
See the full API documentation for all endpoints and parameters.
Frequently Asked Questions
What is a .woff file?
A .woff file is a Web Open Font Format file. WOFF File Format 1.0[64]
What are the magic bytes for .woff files?
The magic bytes for Web Open Font Format files are 77 4F 46 46 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .woff file?
To validate a .woff file, read the first bytes of the file and compare them against the known magic bytes (77 4F 46 46) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .woff files?
There is no officially registered MIME type for .woff files. Systems typically use application/octet-stream as a generic fallback when handling this format.
Is it safe to open .woff files?
Web Open Font Format (.woff) 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.