MAC Address Generator
Generate one or many random MAC addresses, choose the separator and case, and optionally set a vendor OUI prefix — all in your browser.
Addresses are generated locally in your browser — nothing is uploaded.
How to use MAC Address Generator
The MAC Address Generator creates random 48-bit MAC addresses in any format: colon-separated (00:1A:2B:3C:4D:5E), dash-separated (00-1A-2B-3C-4D-5E), or without separators. Configure uppercase or lowercase hex, optionally set a vendor OUI prefix, and generate up to 100 addresses at once. All generation is local — nothing is uploaded.
- Choose the separator format: colon (:), dash (-), or none.
- Select uppercase or lowercase hexadecimal.
- Optionally enter an OUI prefix (e.g. 00:1A:2B) to fix the vendor identifier bytes.
- Set the count (1–100) for bulk generation.
- Click Generate and copy the addresses individually or all at once.
Your data never leaves your device — 100% private processing.
MAC address structure and format
A MAC (Media Access Control) address is a 48-bit (6-byte) unique identifier assigned to network interface controllers. It is conventionally written as six groups of two hexadecimal digits separated by colons or dashes (e.g. 00:1A:2B:3C:4D:5E). The first three bytes (24 bits) form the OUI (Organizationally Unique Identifier) assigned by the IEEE to manufacturers — allowing tools like Wireshark to resolve vendor names. The last three bytes are a device-specific serial number assigned by the manufacturer. Two special bits in the first byte matter: bit 0 (LSB) is the multicast bit — set to 1 for multicast addresses; bit 1 is the locally administered bit — set to 1 for MAC addresses not globally assigned by the IEEE, such as those used in virtual machines, containers, and randomised addresses.
| Format | Example | Common use |
|---|---|---|
| Colon-separated | 00:1A:2B:3C:4D:5E | Linux, macOS, network tools |
| Dash-separated | 00-1A-2B-3C-4D-5E | Windows, IEEE standard notation |
| No separator | 001A2B3C4D5E | Database storage, some APIs |
| Dot-separated (Cisco) | 001A.2B3C.4D5E | Cisco IOS notation (groups of 4) |
MAC address randomisation and privacy
Modern operating systems randomise the MAC address used for Wi-Fi scanning to prevent tracking. When your phone scans for networks, it broadcasts probe requests with a random locally administered MAC rather than its real hardware address. This prevents tracking your physical location across different networks based on your hardware address. iOS, Android, Windows 10+, and Linux all support MAC randomisation by default for Wi-Fi scanning; some also randomise the address used when connected to a network. For testing, generating random MAC addresses with locally administered bit set (second hex digit is 2, 6, A, or E) correctly simulates virtualised or randomised hardware addresses.
Glossary
- MAC address
- Media Access Control address — a 48-bit hardware identifier for a network interface, used for communication within a local network segment.
- OUI
- Organizationally Unique Identifier — the first 24 bits of a MAC address assigned by the IEEE to a manufacturer or organisation.
- Multicast
- Network communication addressed to a group of receivers; indicated in MAC addresses by the least significant bit of the first byte being set to 1.
- Locally administered
- A MAC address flag (second LSB of first byte = 1) indicating the address is locally assigned rather than globally unique from a manufacturer.
- NIC
- Network Interface Controller — hardware that connects a computer to a network; each NIC is assigned a globally unique MAC address by the manufacturer.
Related reading
Frequently Asked Questions
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Why use MAC Address Generator?
- No installation — use directly from any browser
- Handles large inputs without crashing or timeouts
- Syntax highlighting and formatted output for readability
- Copy to clipboard shortcut for fast workflow integration
Common use cases
- Validate and format JSON responses from APIs
- Encode/decode Base64 strings during debugging
- Generate UUIDs for database seeds or test data
- Minify CSS or JavaScript before deployment
- Diff two code snippets to spot regressions
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