OutlookPersonalStorage (.pst)
.pst file signature | application/vnd.ms-outlook-pst
Outlook Personal Storage Table (PST) is a data file format created and maintained by Microsoft for use with Microsoft Outlook. It stores email messages, calendars, contacts, tasks, notes, and other mailbox data for local archiving, backup, and transfer between Outlook installations. PST files are generally safe to open, though large or corrupted archives can be difficult to recover, and older ANSI-based PST variants are a legacy format with size limitations.
Magic Bytes
Offset 0
21 42 44 4E
Sources: Wikipedia, Neil Harvey FileSignatures
All Known Signatures
2 signature variants are documented for .pst files across multiple sources.
| Hex Signature | Offset | Sources |
|---|---|---|
| 21 42 44 4E | 0 | Wikipedia, Neil Harvey FileSignatures |
| 21 42 44 4E 2E 2E 2E 2E 53 4D | 0 | Apache Tika |
Extension
.pst
MIME Type
application/vnd.ms-outlook-pst
Byte Offset
0
Risk Level
Safe
Validation Code
How to validate .pst files in Python
def is_pst(file_path: str) -> bool:
"""Check if file is a valid PST by magic bytes."""
signature = bytes([0x21, 0x42, 0x44, 0x4E])
with open(file_path, "rb") as f:
return f.read(4) == signatureHow to validate .pst files in Node.js
function isPST(buffer: Buffer): boolean {
const signature = Buffer.from([0x21, 0x42, 0x44, 0x4E]);
return buffer.subarray(0, 4).equals(signature);
}How to validate .pst files in Go
func IsPST(data []byte) bool {
signature := []byte{0x21, 0x42, 0x44, 0x4E}
if len(data) < 4 {
return false
}
return bytes.Equal(data[:4], signature)
}API Endpoint
/api/v1/pst
curl https://filesignature.org/api/v1/pst
See the full API documentation for all endpoints and parameters.
Related Formats
Frequently Asked Questions
What is a .pst file?
A .pst file is a OutlookPersonalStorage file. Outlook Personal Storage Table (PST) is a data file format created and maintained by Microsoft for use with Microsoft Outlook. It stores email messages, calendars, contacts, tasks, notes, and other mailbox data for local archiving, backup, and transfer between Outlook installations. PST files are generally safe to open, though large or corrupted archives can be difficult to recover, and older ANSI-based PST variants are a legacy format with size limitations.
What are the magic bytes for .pst files?
The magic bytes for OutlookPersonalStorage files are 21 42 44 4E at byte offset 0. These bytes uniquely identify the file format regardless of the file extension.
How do I validate a .pst file?
To validate a .pst file, read the first bytes of the file and compare them against the known magic bytes (21 42 44 4E) at offset 0. This is more reliable than checking the file extension alone, as extensions can be renamed.
What is the MIME type for .pst files?
The primary MIME type for .pst files is application/vnd.ms-outlook-pst.
Is it safe to open .pst files?
OutlookPersonalStorage (.pst) 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.