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XSL (.xsl)

.xsl file signature | application/xml

Safe

Magic Bytes

Offset 0
3C 3F 78 6D 6C

Sources: Apache Tika

All Known Signatures

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

Hex Signature Offset Sources
3C 3F 78 6D 6C 0 Apache Tika
3C 3F 58 4D 4C 0 Apache Tika
EF BB BF 3C 3F 78 6D 6C 0 Apache Tika
FF FE 3C 00 3F 00 78 00 6D 00 6C 00 0 Apache Tika
FE FF 00 3C 00 3F 00 78 00 6D 00 6C 0 Apache Tika
3C 21 2D 2D 0 Apache Tika

Extension

.xsl

MIME Type

application/xml

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .xsl files in Python

Python 
def is_xsl(file_path: str) -> bool:
    """Check if file is a valid XSL by magic bytes."""
    signature = bytes([0x3C, 0x3F, 0x78, 0x6D, 0x6C])
    with open(file_path, "rb") as f:
        return f.read(5) == signature

How to validate .xsl files in Node.js

Node.js 
function isXSL(buffer: Buffer): boolean {
  const signature = Buffer.from([0x3C, 0x3F, 0x78, 0x6D, 0x6C]);
  return buffer.subarray(0, 5).equals(signature);
}

How to validate .xsl files in Go

Go 
func IsXSL(data []byte) bool {
    signature := []byte{0x3C, 0x3F, 0x78, 0x6D, 0x6C}
    if len(data) < 5 {
        return false
    }
    return bytes.Equal(data[:5], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .xsl file?

A .xsl file is a XSL file.

What are the magic bytes for .xsl files?

The magic bytes for XSL files are 3C 3F 78 6D 6C at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .xsl file?

To validate a .xsl file, read the first bytes of the file and compare them against the known magic bytes (3C 3F 78 6D 6C) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .xsl files?

The primary MIME type for .xsl files is application/xml.

Is it safe to open .xsl files?

XSL (.xsl) 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.