NOTE: — 2021-May — There’s a related post on how to spoof your MAC address, free, using a script. See that here. It works on Big Sur, in case you’re wondering.
For some Apple Mac users a “mac address” may sound like a reference to the current location of your computer. In this case, however, MAC refers not to your computer but to the unique Media Access Control code assigned to every device capable of connecting to a network. The Wi-Fi chip in your Apple computer, iPad, iPod, iPhone, Kindle, Android phone, Windows computer, etc., has a hardware level identifier. This enables networks and other network capable devices (such as your wi-fi router) to differentiate one device from another. a MAC address takes the following format: 01-23-45-67-89-ab
Why change your MAC address?
There are situations where it is useful to temporarily change your device’s MAC address. As it is hardware encoded, it can only be changed temporarily. It will revert back when you reboot your device. Changing your MAC address is commonly called spoofing the MAC address.
For instance, right now I am in London Heathrow airport. They provide free wi-fi access, and yet in their wisdom Heathrow decided to only allow a device to connect for 45 minutes. I have a 4 hour wait for my next flight. I’ve not yet reached the end of the 45 minutes, but there’s a chance the network will lock my MacBook out once the 45 minutes is over. Quite why they have a time limit is a mystery to me. Every person here in the departure area is obviously destined to get on a plane and leave. It’s not as though people can come in here and make use of the Internet without being a passenger.
Because the network depends on my MacBook’s MAC address to identify it, changing the MAC address gives me a fresh start. As far as the network is concerned my new MAC address represents a different device from the one that just used up 45 minutes of air time. Some coffee shops are also implementing time limits, as do many public libraries. I can understand their logic for doing so. It prevents someone from buying one cup of coffee and then spending the rest of the day using the cafe as their office. My local library (in New Zealand) also enforces a time limit. That, again, does not make sense to me. The library is a public service, and providing Internet access is part of the services they offer. People don’t get kicked out after reading books in the library for 2 hours. Why are they booted from the Internet? There are plenty of other situations where changing a MAC address may come in handy.
How to change your MAC address
You can change the MAC address in the Terminal (I am referring to Terminal.app as opposed to an Airport Terminal). There are plenty of articles online explaining how to go about that method. But it is much easier to use an app fit for the purpose. Not only will these apps change your MAC address, they will also generate a new random MAC address. The two apps I have used and recommend are:
UPDATE: 2021 — This app has not been updated in a long time. It currently (v0.2.0b21) doesn’t work on MacOS Catalina (v10.15) and above.
This is the big daddy of MAC address spoofing apps. It will let you spoof the manufacturer/brand of device too, or ensure the brand remains consistent. For instance, you can generate a MAC address that is a valid Apple device MAC address as opposed to any random device brand. A very comprehensive list of device manufacturers is included in MacDaddyX. Whether or not that feature is useful to you will depend on your purpose for spoofing the MAC address.
This app appears to have been abandoned by the developer. It still works on my OS X 10.8.4 MacBook. You can download it from MacUpdate. It’s also available from the developer’s website. For a smoother app, check out the next option.
WifiSpoof is a more recent app. You can’t select the manufacturer of your spoofed MAC address, but for most people that’s not important. It looks like this:
For most people I would recommend using WifiSpoof. It works well and sits nicely in the menu bar.
UPDATE: 2021 — Wifispoof is now US$19.99 to purchase, via the App Store. To me, that’s seems over priced for the tiny simple task it performs. If you don’t mind parting with $20 to use it, then it’s still an excellent option.
Case in point
Whilst writing this article, I went to use the toilet and speak to an Airline rep. On my return I was faced with the following message: Dear Jonathan, your FREE time has now expired and will be available to you again in 11 hours 36 minutes.
Heathrow’s measly 45 minutes is up. I have 3 hours to wait for my flight. If I had no idea about changing my MAC address it’s about now I could be feeling rather annoyed. Time to change my MAC address.