GUID Regex Python Validator

What Is a GUID?

A GUID is a 128-bit unique identifier often used to label resources like users, sessions, or records. It appears as a string in this format:

xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

Where each x is a hexadecimal digit (0-9, a-f, or A-F). While GUIDs and UUIDs are functionally similar, GUIDs are more common in Microsoft-based systems.

Regex Pattern for GUID in Python

Here’s a regex pattern that accurately validates a standard GUID:

^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-5][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}$

This ensures:

• 8 digits at the beginning

• Followed by three groups of 4 digits (hyphen-separated)

• Ends with 12 hex digits

Python Example to Validate GUID

import re

def is_valid_guid(guid):
    pattern = re.compile(
        r'^[0-9a-fA-F]{8}-'
        r'[0-9a-fA-F]{4}-'
        r'[1-5][0-9a-fA-F]{3}-'
        r'[89abAB][0-9a-fA-F]{3}-'
        r'[0-9a-fA-F]{12}$'
    )
    return bool(pattern.fullmatch(guid))

# Test GUIDs
test_guids = [
    "123e4567-e89b-12d3-a456-426614174000",
    "00112233-4455-6677-8899-aabbccddeeff",
    "invalid-guid-format"
]

for g in test_guids:
    print(f"{g} -> {is_valid_guid(g)}")

Use Cases

• Database Record IDs: Use GUIDs as primary keys for distributed systems.

• Authentication Tokens: Validate GUIDs passed via API headers or query strings.

• Data Synchronization: Match GUIDs in local and remote storage to ensure consistency.

• Debugging Tools: Use it with the IP Address Regex Python Validator to monitor network-based identifiers.

Pro Tips

• Always sanitize GUID inputs—especially from client-side sources.

• Strip leading/trailing whitespaces before validation.

• Combine it with the Date Regex Python Validator when working with time-stamped identifiers.

• Use lowercase GUIDs in systems where case doesn’t matter to maintain consistency.