ALIAS (.alias)
.alias file signature | application/octet-stream
ALIAS is a macOS file-reference format created and maintained by Apple Inc. for storing alias records that point to other files, folders, or volumes. It is used by Finder and applications to preserve access to items after they are moved, renamed, or relocated, and appears in shortcuts, saved documents, and system metadata. The format is a legacy part of classic Mac OS and early macOS workflows; it is generally safe, though aliases can become stale when targets are unavailable.
Magic Bytes
Offset 0
62 6F 6F 6B 00 00 00 00
Sources: Wikipedia
All Known Signatures
2 signature variants are documented for .alias files across multiple sources.
Extension
.alias
MIME Type
application/octet-stream
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .alias files in Python
def is_alias(file_path: str) -> bool:
"""Check if file is a valid ALIAS by magic bytes."""
signature = bytes([0x62, 0x6F, 0x6F, 0x6B, 0x00, 0x00, 0x00, 0x00])
with open(file_path, "rb") as f:
return f.read(8) == signatureHow to validate .alias files in Node.js
function isALIAS(buffer: Buffer): boolean {
const signature = Buffer.from([0x62, 0x6F, 0x6F, 0x6B, 0x00, 0x00, 0x00, 0x00]);
return buffer.subarray(0, 8).equals(signature);
}How to validate .alias files in Go
func IsALIAS(data []byte) bool {
signature := []byte{0x62, 0x6F, 0x6F, 0x6B, 0x00, 0x00, 0x00, 0x00}
if len(data) < 8 {
return false
}
return bytes.Equal(data[:8], signature)
}API Endpoint
/api/v1/alias
curl https://filesignature.org/api/v1/alias
See the full API documentation for all endpoints and parameters.
Frequently Asked Questions
What is a .alias file?
A .alias file is identified by the magic bytes 62 6F 6F 6B 00 00 00 00 at byte offset 0. ALIAS is a macOS file-reference format created and maintained by Apple Inc. for storing alias records that point to other files, folders, or volumes. It is used by Finder and applications to preserve access to items after they are moved, renamed, or relocated, and appears in shortcuts, saved documents, and system metadata. The format is a legacy part of classic Mac OS and early macOS workflows; it is generally safe, though aliases can become stale when targets are unavailable.
What are the magic bytes for .alias files?
The magic bytes for ALIAS files are 62 6F 6F 6B 00 00 00 00 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .alias file?
To validate a .alias file, read the first bytes of the file and compare them against the known magic bytes (62 6F 6F 6B 00 00 00 00) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .alias files?
There is no officially registered MIME type for .alias files. Systems typically use application/octet-stream as a generic fallback when handling this format.
Is it safe to open .alias files?
ALIAS (.alias) 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.