# MAC address inspector — OUI lookup, no upload

> Inspect a MAC address: validate its format and identify the OUI vendor prefix, in your browser. Nothing is uploaded — the address stays in the tab.

Inspect a MAC address — check its format, normalize the notation, and identify the OUI vendor prefix. It works entirely in the browser, with nothing uploaded.

A MAC address's first half identifies its maker, which is handy when auditing a network or spotting an unfamiliar device. The inspector validates the format and surfaces that vendor prefix.

For IP-level work, use the IP converter and CIDR calculator alongside it.

## How to

1. **Enter a MAC.** Paste a MAC address in any common notation.
2. **Inspect.** See the normalized form and the OUI vendor prefix.
3. **Use it.** Identify the device manufacturer or validate the format.

## FAQ

### What is an OUI?

The Organizationally Unique Identifier — the first three bytes of a MAC address — which identifies the hardware manufacturer. The inspector surfaces it from the address.

### Does it normalize different MAC formats?

Yes. Colon, hyphen, and dotted notations are recognized and normalized so you can compare addresses consistently.

### Is the address uploaded?

No. Inspection runs locally, so the MAC stays in the tab.


## Related tools

- [IPv4 / IPv6](https://www.safepaper.app/dev/ip-convert)
- [CIDR calculator](https://www.safepaper.app/dev/cidr)
- [Common ports](https://www.safepaper.app/dev/common-ports)
- [User-Agent parser](https://www.safepaper.app/dev/user-agent)

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Canonical HTML: https://www.safepaper.app/dev/mac-lookup
Markdown: https://www.safepaper.app/dev/mac-lookup.md

There is no upload endpoint — your files are processed in this browser tab. Open your network tab and check.