Skip to content

GRIB (.grib)

.grib file signature | application/octet-stream

Gridded data (commonly weather observations or forecasts) in theWMOGRIBorGRIB2format[89]

Safe

Magic Bytes

Offset 0
47 52 49 42

Sources: Wikipedia

Extension

.grib

MIME Type

application/octet-stream

Byte Offset

0

Risk Level

Safe

Validation Code

How to validate .grib files in Python

Python 
def is_grib(file_path: str) -> bool:
    """Check if file is a valid GRIB by magic bytes."""
    signature = bytes([0x47, 0x52, 0x49, 0x42])
    with open(file_path, "rb") as f:
        return f.read(4) == signature

How to validate .grib files in Node.js

Node.js 
function isGRIB(buffer: Buffer): boolean {
  const signature = Buffer.from([0x47, 0x52, 0x49, 0x42]);
  return buffer.subarray(0, 4).equals(signature);
}

How to validate .grib files in Go

Go 
func IsGRIB(data []byte) bool {
    signature := []byte{0x47, 0x52, 0x49, 0x42}
    if len(data) < 4 {
        return false
    }
    return bytes.Equal(data[:4], signature)
}

API Endpoint

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

See the full API documentation for all endpoints and parameters.

Frequently Asked Questions

What is a .grib file?

A .grib file is a GRIB file. Gridded data (commonly weather observations or forecasts) in theWMOGRIBorGRIB2format[89]

What are the magic bytes for .grib files?

The magic bytes for GRIB files are 47 52 49 42 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.

How do I validate a .grib file?

To validate a .grib file, read the first bytes of the file and compare them against the known magic bytes (47 52 49 42) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.

What is the MIME type for .grib files?

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

Is it safe to open .grib files?

GRIB (.grib) 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.