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FH5 (.fh5)

.fh5 file signature | image/x-freehand

Safe

Magic Bytes

Offset 0
41 47 44 32

Sources: Apache Tika

All Known Signatures

6 signature variants are documented for .fh5 files across multiple sources.

Hex Signature Offset Sources
41 47 44 32 0 Apache Tika
41 47 44 33 0 Apache Tika
41 47 44 34 0 Apache Tika
46 72 65 65 48 61 6E 64 31 30 0 Apache Tika
46 72 65 65 48 61 6E 64 31 31 0 Apache Tika
46 72 65 65 48 61 6E 64 31 32 0 Apache Tika

Extension

.fh5

MIME Type

image/x-freehand

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .fh5 files in Python

Python
def is_fh5(file_path: str) -> bool:
    """Check if file is a valid FH5 by magic bytes."""
    signature = bytes([0x41, 0x47, 0x44, 0x32])
    with open(file_path, "rb") as f:
        return f.read(4) == signature

How to validate .fh5 files in Node.js

Node.js
function isFH5(buffer: Buffer): boolean {
  const signature = Buffer.from([0x41, 0x47, 0x44, 0x32]);
  return buffer.subarray(0, 4).equals(signature);
}

How to validate .fh5 files in Go

Go
func IsFH5(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/fh5
curl https://filesignature.org/api/v1/fh5

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .fh5 file?

A .fh5 file is a FH5 file.

What are the magic bytes for .fh5 files?

The magic bytes for FH5 files are 41 47 44 32 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .fh5 file?

To validate a .fh5 file, read the first bytes of the file and compare them against the known magic bytes (41 47 44 32) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .fh5 files?

The primary MIME type for .fh5 files is image/x-freehand.

Is it safe to open .fh5 files?

FH5 (.fh5) 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.