How do I connect a laptop or phone to a TV?

Most connection failures come down to two things: the TV is showing a different input, or the two devices are on different wifi networks. Checking those first resolves the majority of cases.

What you'll need

• HDMI cable or adapter
• Both devices on the same wifi (optional)

Step by step

1. For a cable connection, use HDMI.It carries picture and sound in one cable. Laptops with only USB-C need an adapter — buy one that explicitly supports video output.
2. Select the correct input on the TV.Press Source or Input and choose the HDMI port you used. Ports are numbered, and choosing the wrong one is the most common reason for 'no signal'.
3. Set the display mode on the laptop.Windows: Windows key plus P. Mac: System Settings, Displays. Choose mirror or extend depending on what you want.
4. Check the sound output separately.Picture often works while sound stays on the laptop. Change the output device in sound settings to the TV.
5. For wireless from a phone, use casting or screen mirroring.AirPlay on Apple devices, Google Cast on Android and Chromecast. Both devices must be on the same wifi network.
6. Check both devices are on the same network.The most common wireless failure. A phone on 5GHz and a TV on 2.4GHz, or one on a guest network, will not see each other.
7. Distinguish casting from mirroring.Casting sends the TV a link to play the content itself, which is more reliable and lets you use the phone for other things. Mirroring copies the screen and is more prone to lag.
8. Restart both devices if they cannot see each other.Casting protocols get stuck. A restart of the phone and the TV resolves most discovery problems.

Tips

• A cheap streaming stick often works better than a smart TV's built-in apps, and adds casting to a TV that lacks it.
• If the picture is cut off at the edges, look for an overscan or 'just scan' setting in the TV's picture options.
• HDMI cables rarely fail but do vary. For 4K at high refresh rates, the cable specification genuinely matters.

Common mistakes

• Not switching the TV to the right input — The TV shows 'no signal' from whatever input it was on, and everything looks broken when nothing is wrong.
• Assuming sound follows the picture — It is a separate output setting. Change the audio output device on the laptop as well.
• Trying to cast across different networks — Casting requires both devices on the same network. Guest networks and separate wifi bands both break it.

Questions people ask