MAC Address Lookup
Validate a MAC and find the vendor behind the OUI prefix
MAC Address
Looks up the OUI via the public macvendors.com API.
MAC Address Lookup — Complete Guide & Instructions
MakeCard MAC Address Lookup validates a hardware address and identifies the manufacturer registered to its OUI — the first three bytes. It accepts common formats like AA:BB:CC:DD:EE:FF, normalizes the input, and resolves the vendor through the public macvendors.com API. Network admins use it to identify unknown devices on a LAN, and curious users to see who made a phone or router chipset.
How to Use MAC Address Lookup
- 1 Enter the MAC address — e.g. AA:BB:CC:DD:EE:FF — or click “Sample” for an example.
- 2 Press “Lookup vendor” (or hit Enter).
- 3 Read the green badge showing the vendor name.
- 4 Check the normalized MAC and the extracted OUI prefix rows below.
- 5 On failure, the red badge explains whether the format or the API call failed.
Key Features & Capabilities
- Validates standard MAC formats before querying.
- Resolves the vendor name via the public macvendors.com OUI registry.
- Shows the normalized MAC and its OUI prefix clearly.
- Sample button loads a working address instantly.
- Distinct error messages for bad format vs unregistered OUI.
Supported Formats & Specifications
| Parameter | Specification |
|---|---|
| Input | 48-bit MAC — AA:BB:CC:DD:EE:FF style separators |
| Lookup Source | macvendors.com public OUI API (external request) |
| Output | Vendor name, normalized MAC, OUI prefix |
| Processing | Format check in-browser; vendor resolved via API |
Practical Everyday Use Cases
- Identifying an unknown device appearing on the router's client list.
- Checking whether a device's NIC is genuine Intel/Realtek/etc.
- Auditing DHCP lease tables and flagging unexpected vendors.
- Classroom demos of how OUI prefixes map to manufacturers.
- Tracing a spoofed or randomized MAC — vendor shows as unregistered.
Pro Tips for Best Results
- Only the first three bytes (OUI) determine the vendor — a randomized or locally administered MAC may return “not found”.
- Many phones now randomize MACs per network; a missing vendor does not mean a rogue device.
- Colons, hyphens and plain hex all resolve to the same OUI — paste whichever format your router shows.
- Vendor names reflect the chipset or brand registrant, which can differ from the product label.
Common Problems & Solutions
The OUI is unregistered or the MAC is locally administered/randomized — increasingly common on modern phones.
The vendor query uses the public macvendors.com API — check your internet connection and try again; the format check itself is offline.
A MAC has exactly six byte pairs; remove pasted extras like interface names or trailing text.
Privacy & Security
100% Client-Side Execution
Vendor resolution sends the MAC address to the public macvendors.com API, as noted in the tool — MakeCard itself does not log or store your lookups.
Frequently Asked Questions
Everything you need to know about using MAC Address Lookup
The OUI (Organizationally Unique Identifier) is the first 24 bits of a MAC address, assigned by the IEEE to a manufacturer — it is what this tool resolves to a vendor name.
Paste the MAC into the field and press Lookup vendor — the tool extracts the OUI and returns the registered company, e.g. Apple, Samsung or Espressif.
Locally administered and randomized MACs (used by phones for privacy) have OUIs not present in the registry, so no vendor is returned.
Only the manufacturer — the OUI reveals who made the network chip, not the model or owner.
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