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Electronic Arts'Interchange Format Files (.iff)

.iff file signature | application/octet-stream

Electronic Arts Interchange File Format (IFF) is a structured container format developed by Electronic Arts for storing interchangeable data across different computer systems. It has been used for audio, images, animations, and other multimedia assets in games and legacy software, particularly on Amiga and related platforms. As a legacy format, it is generally safe to open, though compatibility support may be limited in modern applications.

Safe

Magic Bytes

Offset 0
46 4F 52 4D

Sources: Wikipedia, Gary Kessler

All Known Signatures

15 signature variants are documented for .iff files across multiple sources.

Hex Signature Offset Sources
46 4F 52 4D 0 Wikipedia, Gary Kessler
49 4C 42 4D 0 Wikipedia
38 53 56 58 0 Wikipedia
41 43 42 4D 0 Wikipedia
41 4E 42 4D 0 Wikipedia
41 4E 49 4D 0 Wikipedia
46 41 58 58 0 Wikipedia
46 54 58 54 0 Wikipedia
53 4D 55 53 0 Wikipedia
43 4D 55 53 0 Wikipedia
59 55 56 4E 0 Wikipedia
46 41 4E 54 0 Wikipedia
41 49 46 46 0 Wikipedia
43 41 54 20 0 Gary Kessler
4C 49 53 54 0 Gary Kessler

Extension

.iff

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .iff files in Python

Python 
def is_iff(file_path: str) -> bool:
    """Check if file is a valid IFF by magic bytes."""
    signature = bytes([0x46, 0x4F, 0x52, 0x4D])
    with open(file_path, "rb") as f:
        return f.read(4) == signature

How to validate .iff files in Node.js

Node.js 
function isIFF(buffer: Buffer): boolean {
  const signature = Buffer.from([0x46, 0x4F, 0x52, 0x4D]);
  return buffer.subarray(0, 4).equals(signature);
}

How to validate .iff files in Go

Go 
func IsIFF(data []byte) bool {
    signature := []byte{0x46, 0x4F, 0x52, 0x4D}
    if len(data) < 4 {
        return false
    }
    return bytes.Equal(data[:4], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .iff file?

A .iff file is a Electronic Arts'Interchange Format Files file. Electronic Arts Interchange File Format (IFF) is a structured container format developed by Electronic Arts for storing interchangeable data across different computer systems. It has been used for audio, images, animations, and other multimedia assets in games and legacy software, particularly on Amiga and related platforms. As a legacy format, it is generally safe to open, though compatibility support may be limited in modern applications.

What are the magic bytes for .iff files?

The magic bytes for Electronic Arts'Interchange Format Files files are 46 4F 52 4D at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .iff file?

To validate a .iff file, read the first bytes of the file and compare them against the known magic bytes (46 4F 52 4D) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .iff files?

There is no officially registered MIME type for .iff files. Systems typically use application/octet-stream as a generic fallback when handling this format.

Is it safe to open .iff files?

Electronic Arts'Interchange Format Files (.iff) 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.