Skip to content

A (.a)

.a file signature | application/x-archive

Safe

Magic Bytes

Offset 0
3D 3C 61 72 3E

Sources: Apache Tika

All Known Signatures

2 signature variants are documented for .a files across multiple sources.

Hex Signature Offset Sources
3D 3C 61 72 3E 0 Apache Tika
21 3C 61 72 63 68 3E 0A 0 Apache Tika

Extension

.a

MIME Type

application/x-archive

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .a files in Python

Python
def is_a(file_path: str) -> bool:
    """Check if file is a valid A by magic bytes."""
    signature = bytes([0x3D, 0x3C, 0x61, 0x72, 0x3E])
    with open(file_path, "rb") as f:
        return f.read(5) == signature

How to validate .a files in Node.js

Node.js
function isA(buffer: Buffer): boolean {
  const signature = Buffer.from([0x3D, 0x3C, 0x61, 0x72, 0x3E]);
  return buffer.subarray(0, 5).equals(signature);
}

How to validate .a files in Go

Go
func IsA(data []byte) bool {
    signature := []byte{0x3D, 0x3C, 0x61, 0x72, 0x3E}
    if len(data) < 5 {
        return false
    }
    return bytes.Equal(data[:5], signature)
}

API Endpoint

GET /api/v1/a
curl https://filesignature.org/api/v1/a

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .a file?

A .a file is a A file.

What are the magic bytes for .a files?

The magic bytes for A files are 3D 3C 61 72 3E at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .a file?

To validate a .a file, read the first bytes of the file and compare them against the known magic bytes (3D 3C 61 72 3E) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .a files?

The primary MIME type for .a files is application/x-archive.

Is it safe to open .a files?

A (.a) 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.