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Microsoft Access file (.mdb)

.mdb file signature | application/x-msaccess

Microsoft Access Database

Safe

Magic Bytes

Offset 0
00 01 00 00 53 74 61 6E 64 61 72 64 20 4A 65 74 20 44 42

Sources: Wikipedia, Gary Kessler

All Known Signatures

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

Hex Signature Offset Sources
00 01 00 00 53 74 61 6E 64 61 72 64 20 4A 65 74 20 44 42 0 Wikipedia, Gary Kessler
00 01 00 00 53 74 61 6E 0 Apache Tika

Extension

.mdb

MIME Type

application/x-msaccess

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .mdb files in Python

Python 
def is_mdb(file_path: str) -> bool:
    """Check if file is a valid MDB by magic bytes."""
    signature = bytes([0x00, 0x01, 0x00, 0x00, 0x53, 0x74, 0x61, 0x6E, 0x64, 0x61, 0x72, 0x64, 0x20, 0x4A, 0x65, 0x74, 0x20, 0x44, 0x42])
    with open(file_path, "rb") as f:
        return f.read(19) == signature

How to validate .mdb files in Node.js

Node.js 
function isMDB(buffer: Buffer): boolean {
  const signature = Buffer.from([0x00, 0x01, 0x00, 0x00, 0x53, 0x74, 0x61, 0x6E, 0x64, 0x61, 0x72, 0x64, 0x20, 0x4A, 0x65, 0x74, 0x20, 0x44, 0x42]);
  return buffer.subarray(0, 19).equals(signature);
}

How to validate .mdb files in Go

Go 
func IsMDB(data []byte) bool {
    signature := []byte{0x00, 0x01, 0x00, 0x00, 0x53, 0x74, 0x61, 0x6E, 0x64, 0x61, 0x72, 0x64, 0x20, 0x4A, 0x65, 0x74, 0x20, 0x44, 0x42}
    if len(data) < 19 {
        return false
    }
    return bytes.Equal(data[:19], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .mdb file?

A .mdb file is a Microsoft Access file file. Microsoft Access Database

What are the magic bytes for .mdb files?

The magic bytes for Microsoft Access file files are 00 01 00 00 53 74 61 6E 64 61 72 64 20 4A 65 74 20 44 42 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .mdb file?

To validate a .mdb file, read the first bytes of the file and compare them against the known magic bytes (00 01 00 00 53 74 61 6E 64 61 72 64 20 4A 65 74 20 44 42) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .mdb files?

The primary MIME type for .mdb files is application/x-msaccess.

Is it safe to open .mdb files?

Microsoft Access file (.mdb) 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.