FH4
image/x-freehand
Magic Bytes
Offset: 0
41 47 44 32
The FH4 file format is a legacy vector graphics container developed by Altsys Corporation for use with Aldus FreeHand version 4. It stores scalable vector illustrations, lines, curves, and text layouts primarily used for professional graphic design and print publishing projects. As an obsolete proprietary standard, this format is considered safe but requires specific conversion tools or legacy software for viewing on modern operating systems.
Validation Code
How to validate .fh4 files in Python
Python
def is_fh4(file_path: str) -> bool:
"""Check if file is a valid FH4 by magic bytes."""
signature = bytes([0x41, 0x47, 0x44, 0x32])
with open(file_path, "rb") as f:
return f.read(4) == signatureHow to validate .fh4 files in Node.js
Node.js
function isFH4(buffer: Buffer): boolean {
const signature = Buffer.from([0x41, 0x47, 0x44, 0x32]);
return buffer.subarray(0, 4).equals(signature);
}
Go
func IsFH4(data []byte) bool {
signature := []byte{0x41, 0x47, 0x44, 0x32}
if len(data) < 4 {
return false
}
return bytes.Equal(data[:4], signature)
}API Endpoint
GET
/api/v1/fh4
curl https://filesignature.org/api/v1/fh4