NetCDF (classic format, CDF-1) (.nc)
.nc file signature | application/x-netcdf
NetCDF (classic format, CDF-1) is a scientific data file format developed and maintained by Unidata, part of the University Corporation for Atmospheric Research. It is used to store array-oriented data in meteorology, oceanography, climate research, and other earth sciences, and is supported by many analysis tools and programming libraries. The format is generally safe; however, as with any data file, malformed or specially crafted files may cause issues in poorly implemented readers.
Magic Bytes
Offset 0
43 44 46 01
Sources: Apache Tika, Gary Kessler
All Known Signatures
5 signature variants are documented for .nc files across multiple sources.
| Hex Signature | Offset | Sources |
|---|---|---|
| 43 44 46 01 | 0 | Apache Tika, Gary Kessler |
| 43 44 46 02 | 0 | Apache Tika, Gary Kessler |
| 00 6D 02 | 0 | Gary Kessler |
| 00 6D 03 | 0 | Gary Kessler |
| 43 44 46 | 0 | Gary Kessler |
Extension
.nc
MIME Type
application/x-netcdf
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .nc files in Python
def is_nc(file_path: str) -> bool:
"""Check if file is a valid NC by magic bytes."""
signature = bytes([0x43, 0x44, 0x46, 0x01])
with open(file_path, "rb") as f:
return f.read(4) == signatureHow to validate .nc files in Node.js
function isNC(buffer: Buffer): boolean {
const signature = Buffer.from([0x43, 0x44, 0x46, 0x01]);
return buffer.subarray(0, 4).equals(signature);
}How to validate .nc files in Go
func IsNC(data []byte) bool {
signature := []byte{0x43, 0x44, 0x46, 0x01}
if len(data) < 4 {
return false
}
return bytes.Equal(data[:4], signature)
}API Endpoint
/api/v1/nc
curl https://filesignature.org/api/v1/nc
See the full API documentation for all endpoints and parameters.
Related Formats
Frequently Asked Questions
What is a .nc file?
A .nc file is a NetCDF (classic format, CDF-1) file. NetCDF (classic format, CDF-1) is a scientific data file format developed and maintained by Unidata, part of the University Corporation for Atmospheric Research. It is used to store array-oriented data in meteorology, oceanography, climate research, and other earth sciences, and is supported by many analysis tools and programming libraries. The format is generally safe; however, as with any data file, malformed or specially crafted files may cause issues in poorly implemented readers.
What are the magic bytes for .nc files?
The magic bytes for NetCDF (classic format, CDF-1) files are 43 44 46 01 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .nc file?
To validate a .nc file, read the first bytes of the file and compare them against the known magic bytes (43 44 46 01) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .nc files?
The primary MIME type for .nc files is application/x-netcdf.
Is it safe to open .nc files?
NetCDF (classic format, CDF-1) (.nc) 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.