Google Chromium patch update (.crx)
.crx file signature | application/x-chrome-package
Google Chromeextension[48]or packaged app[49]
Magic Bytes
Offset 0
43 72 32 34
Sources: Apache Tika, Wikipedia, Gary Kessler
All Known Signatures
2 signature variants are documented for .crx files across multiple sources.
| Hex Signature | Offset | Sources |
|---|---|---|
| 43 72 32 34 | 0 | Apache Tika, Wikipedia, Gary Kessler |
| 43 72 4F 44 | 0 | Gary Kessler |
Extension
.crx
MIME Type
application/x-chrome-package
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .crx files in Python
def is_crx(file_path: str) -> bool:
"""Check if file is a valid CRX by magic bytes."""
signature = bytes([0x43, 0x72, 0x32, 0x34])
with open(file_path, "rb") as f:
return f.read(4) == signatureHow to validate .crx files in Node.js
function isCRX(buffer: Buffer): boolean {
const signature = Buffer.from([0x43, 0x72, 0x32, 0x34]);
return buffer.subarray(0, 4).equals(signature);
}How to validate .crx files in Go
func IsCRX(data []byte) bool {
signature := []byte{0x43, 0x72, 0x32, 0x34}
if len(data) < 4 {
return false
}
return bytes.Equal(data[:4], signature)
}API Endpoint
/api/v1/crx
curl https://filesignature.org/api/v1/crx
See the full API documentation for all endpoints and parameters.
Frequently Asked Questions
What is a .crx file?
A .crx file is a Google Chromium patch update file. Google Chromeextension[48]or packaged app[49]
What are the magic bytes for .crx files?
The magic bytes for Google Chromium patch update files are 43 72 32 34 at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .crx file?
To validate a .crx file, read the first bytes of the file and compare them against the known magic bytes (43 72 32 34) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .crx files?
The primary MIME type for .crx files is application/x-chrome-package.
Is it safe to open .crx files?
Google Chromium patch update (.crx) 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.