How to wake a computer from your phone with Wake-on-LAN

Wake-on-LAN lets you switch on a sleeping or powered-off computer by sending it a special network message, called a magic packet, from your phone. You turn it on in the computer's firmware and network settings, note its MAC address, then send the packet with a Wake-on-LAN Android app. It works most reliably over a wired connection on the same home network.

What is Wake-on-LAN?

Wake-on-LAN, often shortened to WoL, is a feature built into many network adapters. While the computer sleeps, the network card stays powered just enough to listen. When it sees a magic packet containing its own MAC address, it tells the computer to wake up.

People use it to:

• Turn on a home PC to stream games to a phone or TV.
• Wake a media server only when needed.
• Reach a work computer at home without leaving it on all day.

What you need

• A computer whose network adapter and motherboard support Wake-on-LAN. Most desktops with a wired port do.
• A wired Ethernet connection, ideally. Waking over Wi-Fi is supported on some laptops, but it is less common and less reliable.
• Power to the computer. It must be plugged in, and on a laptop the charger usually needs to be connected.
• The computer's MAC address and local IP address.
• Your phone on the same home network, for the simplest setup.

Step 1: turn it on in the computer's firmware

The firmware is the BIOS or UEFI setup screen you reach by pressing a key while the computer starts. The setting is often called "Wake on LAN", "Power on by PCI-E" or "Resume by LAN". Names differ by motherboard maker, so check the manual if you cannot find it. Turn it on, save and restart.

Some computers also have an energy-saving option that cuts power to the network port when the machine is off. If you find one, turn it off, or the network card will not be able to listen.

Step 2: turn it on in the operating system

On Windows, open Device Manager, find your network adapter, and look in its properties for power management and advanced settings. Allow the device to wake the computer, and enable options named "Wake on Magic Packet" or similar. Windows' fast startup feature can stop a fully shut-down PC from waking, so if waking from shutdown fails, try turning fast startup off, or test from sleep first.

On macOS, look for a "wake for network access" option in the energy or battery settings. On Linux, the network tools let you enable magic packet wake on the adapter.

Step 3: find the MAC address and IP

You need the MAC address of the network adapter that will receive the packet. On Windows you can see it in the network adapter's details. You can also look it up in your router's list of connected devices, where it appears next to the computer's name. See how to see who is connected to your Wi-Fi.

While you are in the router, consider reserving a fixed local IP for the computer, sometimes called a DHCP reservation, so its address does not change.

Step 4: send Wake-on-LAN from your Android phone

1. Connect your Android phone to the same home Wi-Fi as the computer.
2. Open a Wake-on-LAN Android tool and add the computer.
3. Enter its MAC address. Some tools also ask for the broadcast address of your network, which for many home networks ends in .255.
4. Put the computer to sleep, or shut it down if you set that up.
5. Send the packet.
6. Give it a few seconds, then check whether the computer is on, for example with a ping to its IP address.

Waking a computer when you are away from home

Magic packets are normally broadcast on your local network, so they do not cross the internet by themselves. There are two common ways round this:

• A VPN into your home network. Once your phone is connected through the VPN, it behaves as if it were at home, and you can send the packet as usual. This is the safer choice.
• Port forwarding on the router. Some people forward a port to the broadcast address. It can work, but it exposes a port to the internet and is not supported by every router. Read what an open port is before you try it.

Neither will work if your provider uses carrier-grade NAT and you have no public IP of your own. Our guide what is my IP address explains how to tell.

Troubleshooting

If Wake-on-LAN from Android does not work first time, check these common causes.

• Nothing happens from shutdown, but it works from sleep: check fast startup on Windows and the firmware power settings.
• It worked once, then stopped: a driver or system update may have reset the adapter's power settings.
• It does not work on Wi-Fi: try a cable. Wake-on-Wi-Fi support is limited.
• The network light on the computer is off when it is shut down: the port has no power, so it cannot listen. Look for an energy-saving setting in the firmware.
• It wakes at random: some adapters wake on any network activity. Enable "magic packet only" if that option exists.

How CellRadar helps

CellRadar includes a Wake-on-LAN tool among its network tools, so you can send a magic packet from your phone. Its Device Scanner shows the devices on your Wi-Fi with names and makers, which helps you find the computer, and the ping tool lets you check it woke up.

Frequently asked questions

Does Wake-on-LAN work over Wi-Fi?

Sometimes, on laptops that support it, but it is less common and less reliable than a wired connection. For dependable results, use Ethernet.

Can I wake a laptop with the lid closed?

Often yes, if it is plugged in, connected by cable and set to allow network wake. Behaviour varies between models.

Is Wake-on-LAN a security risk?

On your home network the risk is small, because the packet only switches the computer on. Exposing it to the internet through port forwarding adds risk, so a VPN is a safer way to wake it from outside.

Why do I need the MAC address and not just the IP?

A sleeping computer is not actively using its IP address. The magic packet is recognised by the network card's MAC address, which it listens for even while asleep.