PPM (.ppm)
.ppm file signature | image/x-portable-pixmap
Portable Pixmap (PPM) is a simple raster image format from the Netpbm family, originally created by Jef Poskanzer and maintained through the Netpbm project. It is used for basic image storage, conversion workflows, and as an intermediate format in graphics processing and academic software. PPM is a legacy, uncompressed format with minimal metadata, and it generally poses little security risk beyond the usual caution when handling untrusted image files.
Magic Bytes
Offset 0
50 33
Sources: Apache Tika
All Known Signatures
3 signature variants are documented for .ppm files across multiple sources.
| Hex Signature | Offset | Sources |
|---|---|---|
| 50 33 | 0 | Apache Tika |
| 50 33 0A | 0 | Wikipedia |
| 50 36 0A | 0 | Wikipedia |
Extension
.ppm
MIME Type
image/x-portable-pixmap
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .ppm files in Python
def is_ppm(file_path: str) -> bool:
"""Check if file is a valid PPM by magic bytes."""
signature = bytes([0x50, 0x33])
with open(file_path, "rb") as f:
return f.read(2) == signatureHow to validate .ppm files in Node.js
function isPPM(buffer: Buffer): boolean {
const signature = Buffer.from([0x50, 0x33]);
return buffer.subarray(0, 2).equals(signature);
}How to validate .ppm files in Go
func IsPPM(data []byte) bool {
signature := []byte{0x50, 0x33}
if len(data) < 2 {
return false
}
return bytes.Equal(data[:2], signature)
}API Endpoint
/api/v1/ppm
curl https://filesignature.org/api/v1/ppm
See the full API documentation for all endpoints and parameters.
Related Formats
Frequently Asked Questions
What is a .ppm file?
A .ppm file is identified by the magic bytes 50 33 at byte offset 0. Portable Pixmap (PPM) is a simple raster image format from the Netpbm family, originally created by Jef Poskanzer and maintained through the Netpbm project. It is used for basic image storage, conversion workflows, and as an intermediate format in graphics processing and academic software. PPM is a legacy, uncompressed format with minimal metadata, and it generally poses little security risk beyond the usual caution when handling untrusted image files.
What are the magic bytes for .ppm files?
The magic bytes for PPM files are 50 33 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .ppm file?
To validate a .ppm file, read the first bytes of the file and compare them against the known magic bytes (50 33) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .ppm files?
The primary MIME type for .ppm files is image/x-portable-pixmap.
Is it safe to open .ppm files?
PPM (.ppm) 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.