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MYI (.myi)

.myi file signature | application/x-mysql-misam-compressed-index

MYI is a MyISAM index file used by MySQL and MariaDB to store table indexing information for the MyISAM storage engine. It is primarily used alongside database tables to support indexed queries, record lookups, and table maintenance operations in legacy MySQL deployments. The format is generally safe, though it is a legacy component of older MyISAM-based database systems and may be replaced by newer storage engines in modern applications.

Safe

Magic Bytes

Offset 0
FE FE 06

Sources: Apache Tika

All Known Signatures

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

Hex Signature Offset Sources
FE FE 06 0 Apache Tika
FE FE 07 0 Apache Tika

Extension

.myi

MIME Type

application/x-mysql-misam-compressed-index

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .myi files in Python

Python 
def is_myi(file_path: str) -> bool:
    """Check if file is a valid MYI by magic bytes."""
    signature = bytes([0xFE, 0xFE, 0x06])
    with open(file_path, "rb") as f:
        return f.read(3) == signature

How to validate .myi files in Node.js

Node.js 
function isMYI(buffer: Buffer): boolean {
  const signature = Buffer.from([0xFE, 0xFE, 0x06]);
  return buffer.subarray(0, 3).equals(signature);
}

How to validate .myi files in Go

Go 
func IsMYI(data []byte) bool {
    signature := []byte{0xFE, 0xFE, 0x06}
    if len(data) < 3 {
        return false
    }
    return bytes.Equal(data[:3], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .myi file?

A .myi file is identified by the magic bytes FE FE 06 at byte offset 0. MYI is a MyISAM index file used by MySQL and MariaDB to store table indexing information for the MyISAM storage engine. It is primarily used alongside database tables to support indexed queries, record lookups, and table maintenance operations in legacy MySQL deployments. The format is generally safe, though it is a legacy component of older MyISAM-based database systems and may be replaced by newer storage engines in modern applications.

What are the magic bytes for .myi files?

The magic bytes for MYI files are FE FE 06 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .myi file?

To validate a .myi file, read the first bytes of the file and compare them against the known magic bytes (FE FE 06) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .myi files?

The primary MIME type for .myi files is application/x-mysql-misam-compressed-index.

Is it safe to open .myi files?

MYI (.myi) 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.