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NB (.nb)

.nb file signature | application/mathematica

Notebook (NB) is a file format created and maintained by Wolfram Research for Wolfram Mathematica. It is used to store interactive computational notebooks containing text, formulas, code, graphics, and results for scientific, engineering, and mathematical work. The format is generally safe, though notebooks can evaluate embedded Wolfram Language code when opened, so files from untrusted sources should be reviewed before execution.

Safe

Magic Bytes

Offset 0
28 2A 2A

Sources: Apache Tika

All Known Signatures

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

Hex Signature Offset Sources
28 2A 2A 0 Apache Tika
28 2A 20 0 Apache Tika

Extension

.nb

MIME Type

application/mathematica

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .nb files in Python

Python 
def is_nb(file_path: str) -> bool:
    """Check if file is a valid NB by magic bytes."""
    signature = bytes([0x28, 0x2A, 0x2A])
    with open(file_path, "rb") as f:
        return f.read(3) == signature

How to validate .nb files in Node.js

Node.js 
function isNB(buffer: Buffer): boolean {
  const signature = Buffer.from([0x28, 0x2A, 0x2A]);
  return buffer.subarray(0, 3).equals(signature);
}

How to validate .nb files in Go

Go 
func IsNB(data []byte) bool {
    signature := []byte{0x28, 0x2A, 0x2A}
    if len(data) < 3 {
        return false
    }
    return bytes.Equal(data[:3], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Related Formats

.ma .mb

Frequently Asked Questions

What is a .nb file?

A .nb file is identified by the magic bytes 28 2A 2A at byte offset 0. Notebook (NB) is a file format created and maintained by Wolfram Research for Wolfram Mathematica. It is used to store interactive computational notebooks containing text, formulas, code, graphics, and results for scientific, engineering, and mathematical work. The format is generally safe, though notebooks can evaluate embedded Wolfram Language code when opened, so files from untrusted sources should be reviewed before execution.

What are the magic bytes for .nb files?

The magic bytes for NB files are 28 2A 2A at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .nb file?

To validate a .nb file, read the first bytes of the file and compare them against the known magic bytes (28 2A 2A) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .nb files?

The primary MIME type for .nb files is application/mathematica.

Is it safe to open .nb files?

NB (.nb) 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.