Which company owns MAC address prefix C4:57:81?

MAC address prefix C4:57:81 is registered to Wingtech Group (HongKong) Limited in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C4:57:81 has a network interface built by Wingtech Group (HongKong) Limited.

What is the OUI C4:57:81?

C4:57:81 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Wingtech Group (HongKong) Limited. It covers every address from C4:57:81:00:00:00 to C4:57:81:FF:FF:FF, or 16,777,216 addresses in total. It is also written C4-57-81.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in C4:57:81:00:00:00 that is C4:57:81 — and look that prefix up in the IEEE OUI registry. If the second-lowest bit of the first octet is set, the address is locally administered (a randomized or private MAC), which belongs to no manufacturer and will not resolve; modern phones and laptops use these by default on each network.

Where is Wingtech Group (HongKong) Limited located?

Wingtech Group (HongKong) Limited is listed at FLAT/RM 1903 19/F PODIUM PLAZA 5HANOI ROAD TSIM SHA TSUI Hong Kong Hong Kong HK 999077 in the IEEE OUI registry entry for C4:57:81. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Wingtech Group (HongKong) Limited

MAC address prefix C4:57:81 is registered to Wingtech Group (HongKong) Limited in the IEEE OUI registry. Any device whose MAC address begins with C4:57:81 has a network interface built by Wingtech Group (HongKong) Limited. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address — it covers every MAC from C4:57:81:00:00:00 to C4:57:81:FF:FF:FF.

OUI prefix: C4:57:81
Hyphen form: C4-57-81
MAC range: C4:57:81:00:00:00 – C4:57:81:FF:FF:FF
Addresses in block: 16,777,216
Organization: Wingtech Group (HongKong) Limited
Address: FLAT/RM 1903 19/F PODIUM PLAZA 5HANOI ROAD TSIM SHA TSUI Hong Kong Hong Kong HK 999077
Source: IEEE OUI registry

Have a full MAC address? Look it up— we'll also tell you if it's a randomized (private) address rather than a real manufacturer prefix.

Assignment history (2)

The IEEE registry publishes current state only — this is the change record we've kept since we started tracking it daily.

2024-02-15Assigned to "Wingtech Group (HongKong) Limited"
archived source →
2026-07-17Assigned to "Wingtech Group (HongKong) Limited"

Nearby in the registry

The prefixes assigned immediately before and after C4:57:81:

FAQ

Which company owns MAC address prefix C4:57:81?: MAC address prefix C4:57:81 is registered to Wingtech Group (HongKong) Limited in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C4:57:81 has a network interface built by Wingtech Group (HongKong) Limited.
What is the OUI C4:57:81?: C4:57:81 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Wingtech Group (HongKong) Limited. It covers every address from C4:57:81:00:00:00 to C4:57:81:FF:FF:FF, or 16,777,216 addresses in total. It is also written C4-57-81.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in C4:57:81:00:00:00 that is C4:57:81 — and look that prefix up in the IEEE OUI registry. If the second-lowest bit of the first octet is set, the address is locally administered (a randomized or private MAC), which belongs to no manufacturer and will not resolve; modern phones and laptops use these by default on each network.
Where is Wingtech Group (HongKong) Limited located?: Wingtech Group (HongKong) Limited is listed at FLAT/RM 1903 19/F PODIUM PLAZA 5HANOI ROAD TSIM SHA TSUI Hong Kong Hong Kong HK 999077 in the IEEE OUI registry entry for C4:57:81. This is the address the organization registered with the IEEE, which may differ from its current operating address.