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MAC Address Validation
Web & Network
Validates MAC addresses in colon-separated (AA:BB:CC:DD:EE:FF) or hyphen-separated (AA-BB-CC-DD-EE-FF) formats.
/^([0-9A-Fa-f]{2}[:-]){5}([0-9A-Fa-f]{2})$/How it works
A MAC address is a 48-bit hardware identifier represented as six groups of two hexadecimal digits. This pattern accepts both colon and hyphen separators. It does not accept the Cisco dot-notation format (AAAA.BBBB.CCCC).
Test Cases
Should Match
- 00:1A:2B:3C:4D:5E
- AA-BB-CC-DD-EE-FF
- ff:ff:ff:ff:ff:ff
Should NOT Match
- 00:1A:2B:3C:4D
- GG:HH:II:JJ:KK:LL
- 001A.2B3C.4D5E
Quick Summary
Validates MAC addresses in colon (AA:BB:CC:DD:EE:FF) or hyphen (AA-BB-CC-DD-EE-FF) notation. Case-insensitive. Does not match Cisco dot notation (AAAA.BBBB.CCCC).
Key Takeaways
Key Takeaways
- Accepts both : and - as separators (but not mixed in the same address)
- Case-insensitive, both uppercase and lowercase hex digits are valid
- Does not match Cisco dot notation, add AAAA.BBBB.CCCC alternation if needed
- The broadcast address FF:FF:FF:FF:FF:FF is a valid match
Use Cases
When to use it
- Validating MAC address inputs in network management tools
- Parsing ARP tables or DHCP lease files
- Filtering network device registrations
Watch out
Common Mistakes
- Mixing separators in the same address, the pattern requires consistent separators
- Not normalizing to a canonical format (e.g., always lowercase with colons) before storage
FAQ
MAC Address Validation, Frequently Asked
Are MAC addresses unique?
Theoretically yes, the first 3 bytes (OUI) identify the manufacturer and the last 3 are device-specific. In practice, MAC addresses can be spoofed.
How do I normalize a MAC address?
Strip separators, lowercase all hex digits, then reinsert colons: 'aa:bb:cc:dd:ee:ff'.