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An Object Linking and Embedding (.xla)

.xla file signature | application/vnd.ms-excel

An Object Linking and Embedding (OLE) Compound File (CF) (i.e.,OLECF)file format, known asCompound Binary File formatby Microsoft, used byMicrosoft Office 97-2003 applications (Word, Powerpoint, Excel, Wizard). Part ofMicrosoft'sStructured Storage (MSS)architecture for Component Object Model (COM)-basedoperating systems.[See also Excel, Outlook, PowerPoint, and Word "subheaders" at byte offset 512 (0x200).]There appear to several subheader formats and a dearth of documentation.There have been re

Safe

Magic Bytes

Offset 0
D0 CF 11 E0 A1 B1 1A E1

Sources: Apache Tika, Gary Kessler

All Known Signatures

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

Hex Signature Offset Sources
D0 CF 11 E0 A1 B1 1A E1 0 Apache Tika, Gary Kessler
4D 69 63 72 6F 73 6F 66 74 20 45 78 63 65 6C 20 35 2E 30 20 57 6F 72 6B 73 68 65 65 74 2080 Apache Tika
46 6F 67 6C 69 6F 20 64 69 20 6C 61 76 6F 72 6F 20 4D 69 63 72 6F 73 6F 66 74 20 45 78 63 65 2080 Apache Tika
42 69 66 66 35 2114 Apache Tika
42 69 66 66 35 2121 Apache Tika
CF FA ED FE 0 Gary Kessler

Extension

.xla

MIME Type

application/vnd.ms-excel

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .xla files in Python

Python 
def is_xla(file_path: str) -> bool:
    """Check if file is a valid XLA by magic bytes."""
    signature = bytes([0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1])
    with open(file_path, "rb") as f:
        return f.read(8) == signature

How to validate .xla files in Node.js

Node.js 
function isXLA(buffer: Buffer): boolean {
  const signature = Buffer.from([0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1]);
  return buffer.subarray(0, 8).equals(signature);
}

How to validate .xla files in Go

Go 
func IsXLA(data []byte) bool {
    signature := []byte{0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1}
    if len(data) < 8 {
        return false
    }
    return bytes.Equal(data[:8], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .xla file?

A .xla file is a An Object Linking and Embedding file. An Object Linking and Embedding (OLE) Compound File (CF) (i.e.,OLECF)file format, known asCompound Binary File formatby Microsoft, used byMicrosoft Office 97-2003 applications (Word, Powerpoint, Excel, Wizard). Part ofMicrosoft'sStructured Storage (MSS)architecture for Component Object Model (COM)-basedoperating systems.[See also Excel, Outlook, PowerPoint, and Word "subheaders" at byte offset 512 (0x200).]There appear to several subheader formats and a dearth of documentation.There have been re

What are the magic bytes for .xla files?

The magic bytes for An Object Linking and Embedding files are D0 CF 11 E0 A1 B1 1A E1 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .xla file?

To validate a .xla file, read the first bytes of the file and compare them against the known magic bytes (D0 CF 11 E0 A1 B1 1A E1) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .xla files?

The primary MIME type for .xla files is application/vnd.ms-excel.

Is it safe to open .xla files?

An Object Linking and Embedding (.xla) 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.