EPSI (.epsi)

.epsi file signature | application/postscript

Safe

Magic Bytes

Offset 0


              25 21

Sources: Apache Tika

All Known Signatures

4 signature variants are documented for .epsi files across multiple sources.

Hex Signature	Offset	Sources
25 21	0	Apache Tika
04 25 21	0	Apache Tika
C5 D0 D3 C6	0	Apache Tika
25 21 50 53 2D 41 64 6F 62 65 2D 33 2E 30 20 45 50 53 46 2D 33 2E 30	0	Apache Tika

Extension

.epsi

MIME Type

application/postscript

Byte Offset

Risk Level

Safe

Validation Code

How to validate .epsi files in Python

Python

def is_epsi(file_path: str) -> bool:
    """Check if file is a valid EPSI by magic bytes."""
    signature = bytes([0x25, 0x21])
    with open(file_path, "rb") as f:
        return f.read(2) == signature

How to validate .epsi files in Node.js

Node.js

function isEPSI(buffer: Buffer): boolean {
  const signature = Buffer.from([0x25, 0x21]);
  return buffer.subarray(0, 2).equals(signature);
}

How to validate .epsi files in Go

func IsEPSI(data []byte) bool {
    signature := []byte{0x25, 0x21}
    if len(data) < 2 {
        return false
    }
    return bytes.Equal(data[:2], signature)
}

API Endpoint

GET /api/v1/epsi


              curl https://filesignature.org/api/v1/epsi

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .epsi file?

A .epsi file is a EPSI file.

What are the magic bytes for .epsi files?

The magic bytes for EPSI files are 25 21 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .epsi file?

To validate a .epsi file, read the first bytes of the file and compare them against the known magic bytes (25 21) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .epsi files?

The primary MIME type for .epsi files is application/postscript.

Is it safe to open .epsi files?

EPSI (.epsi) 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.