Playing Something From Your Phone on the TV

Someone has a video on their phone.

The whole family crowds around a six-inch screen.

You know the television can show it.

But the button that does that has disappeared.

Two different things are going on here, and people mix them up daily.

What does casting actually do?

Casting sounds like your phone is sending the video across.

It is not.

The phone sends a short message saying play this, from here.

Then it steps aside.

The television fetches the video from the internet itself.

Your phone becomes a remote control, and that is the useful part.

You can lock it, take a call, or open something else.

The film keeps playing.

The battery lasts too, because the phone is no longer doing the work.

Casting only works inside apps that support it, which mostly means streaming apps.

Mirroring copies whatever is on your phone screen onto the television, live.

Notifications, home screen, wrong turns and all.

It is the right choice for holiday photos, a document, or any app without a cast button.

The cost is that your phone must stay awake and unlocked.

So the battery drains and calls interrupt.

There is usually a small delay as well.

That makes mirroring poor for anything fast moving.

A simple rule: cast for streaming apps, mirror for your own content.

Most of the time they are sitting on two different Wi-Fi networks.

Many routers now broadcast two of them, often ending in 2.4G and 5G.

For this purpose those count as separate networks.

Put both devices on the same one and the button usually returns.

Guest Wi-Fi is the next culprit.

Guest networks deliberately hide devices from each other.

If the network is already the same, close the app fully and reopen it.

Then restart the television.

Office, hostel and hotel networks often block casting altogether.

There is nothing to fix at your end there.

Phone and television also have to speak the same casting system, so check what your set supports.