Which company owns MAC address prefix 8C:20:F1?

MAC address prefix 8C:20:F1 is registered to OpenAI in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 8C:20:F1 has a network interface built by OpenAI.

What is the OUI 8C:20:F1?

8C:20:F1 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to OpenAI. It covers every address from 8C:20:F1:00:00:00 to 8C:20:F1:FF:FF:FF, or 16,777,216 addresses in total. It is also written 8C-20-F1.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 8C:20:F1:00:00:00 that is 8C:20:F1 — 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 OpenAI located?

OpenAI is listed at 1455 3rd Street San Francisco CA US 94158 in the IEEE OUI registry entry for 8C:20:F1. This is the address the organization registered with the IEEE, which may differ from its current operating address.

OpenAI

MAC address prefix 8C:20:F1 is registered to OpenAI in the IEEE OUI registry. Any device whose MAC address begins with 8C:20:F1 has a network interface built by OpenAI. 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 8C:20:F1:00:00:00 to 8C:20:F1:FF:FF:FF.

OUI prefix: 8C:20:F1
Hyphen form: 8C-20-F1
MAC range: 8C:20:F1:00:00:00 – 8C:20:F1:FF:FF:FF
Addresses in block: 16,777,216
Organization: OpenAI
Address: 1455 3rd Street San Francisco CA US 94158
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.

2026-06-20Assigned to "OpenAI"
archived source →
2026-07-17Assigned to "OpenAI"

Nearby in the registry

The prefixes assigned immediately before and after 8C:20:F1:

FAQ

Which company owns MAC address prefix 8C:20:F1?: MAC address prefix 8C:20:F1 is registered to OpenAI in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 8C:20:F1 has a network interface built by OpenAI.
What is the OUI 8C:20:F1?: 8C:20:F1 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to OpenAI. It covers every address from 8C:20:F1:00:00:00 to 8C:20:F1:FF:FF:FF, or 16,777,216 addresses in total. It is also written 8C-20-F1.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 8C:20:F1:00:00:00 that is 8C:20:F1 — 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 OpenAI located?: OpenAI is listed at 1455 3rd Street San Francisco CA US 94158 in the IEEE OUI registry entry for 8C:20:F1. This is the address the organization registered with the IEEE, which may differ from its current operating address.