How to use a MAC address validator
Use the single view to inspect the detected format, hexadecimal digit count, byte length, canonical value, address flags, and errors. Bulk results keep each nonblank submitted row so you can review invalid values and repeated hexadecimal values together.
Validate a MAC address in one field
- Select
Single Address. - Enter a candidate in
MAC address. The validation result updates as you type. - For several values, select
Bulk Addresses, then paste one address per line or separate entries with commas. - Choose
Copy CSVto copy the bulk results, or chooseDownload CSVto save them.
Accepted MAC address notation and flags
The validator accepts 12 hexadecimal digits for a 6-byte EUI-48 address or 16 for an 8-byte EUI-64 extended identifier. Recognized notation uses colons, hyphens, Cisco dots, or no separators. A valid result is converted to uppercase colon-separated form.
MAC address: 00:1A:2B:3C:4D:5E
Status: Valid syntax
Canonical (colon-separated): 00:1A:2B:3C:4D:5E
Byte length: 6 bytes (EUI-48)
Unicast / Multicast: Unicast
Administration: Universally administered (burned-in range)For a valid address, the first octet supplies two flags.
- The I/G bit identifies unicast or multicast.
- The U/L bit identifies locally administered or universally administered.
Bulk results and duplicate rows
Bulk Addresses accepts line-separated or comma-separated entries, and blank entries are ignored. You can also use Upload to load a text file. The results table has Address, Status, Flags, Duplicate, and Errors columns. Valid rows show the canonical value; invalid rows keep the submitted value.
Input:
00:1A:2B:3C:4D:5E
001A.2B3C.4D5E
Output:
row 1: Valid
row 2: Valid, Duplicate of row 1Duplicate detection compares the hexadecimal characters after separators and other non-hexadecimal characters are removed. That makes the colon and Cisco-dot entries above match. Duplicate rows remain in the table, and CSV output records the earlier row number.
Errors reported for invalid MAC address input
Non-hexadecimal characters are listed separately. For the digit count, the validator removes colons, hyphens, dots, and whitespace, then counts the remaining hexadecimal characters. A count other than 12 or 16 reports the count found and the expected EUI-48 or EUI-64 length.
Mixed or unrecognized separator groupings can add Separators don't match a recognized colon, hyphen, or dot grouping. The validator checks supplied text and encoded flags. It does not identify a device or vendor, perform an OUI lookup, discover devices, ping, or query a network.
Use the results while cleaning address lists
- Paste an inventory export into
Bulk Addresses, review invalid rows and duplicates, then useDownload CSVto save the table. - Enter a copied address in
MAC addressand check its notation, byte length, and administration flag before recording it. - When lists use different separators, compare their canonical values and duplicate row references in the bulk results.
Choose a validator for another data type
Use Data Validation Tools for other focused checks. Choose IP Address Validator & Bulk Lookup Tool for IPv4, IPv6, or CIDR-style input. Choose Email Validator for email syntax and domain checks, or Base64 Validator for Base64 padding and variant details.
Frequently asked questions
How do I validate a MAC address?
Select Single Address, enter the value in MAC address, and read the validation result. It reports the format, hexadecimal digit count, byte length, canonical value, flags, and errors.
Can I validate multiple MAC addresses at once?
Select Bulk Addresses and paste one address per line or use comma-separated entries. You can also use Upload for a text file, then use Copy CSV or Download CSV.
What does invalid MAC address syntax mean?
The candidate has a non-hexadecimal character, an unexpected hexadecimal digit count, or an unrecognized separator grouping. The error list identifies the character or reports the count found.
Does a MAC address format checker identify the device or vendor?
MAC Address Validator checks supplied text and reads the I/G and U/L bits. It performs no vendor or OUI lookup and does not scan a network.