What Google Cast Does and How to Start

Google Cast is the technology that lets you send video, music, photos, or your entire screen from your phone, tablet, or computer to a TV that has a Chromecast device plugged in. When you cast, you're not mirroring your device's screen like you might with a cable — instead, you're telling the Chromecast to fetch the content directly from the internet or from your device and play it on the TV. Your phone stays in your pocket and keeps working normally while the show plays on the big screen.

To cast anything, you need three things: a device with Google Cast built in (a phone, tablet, or computer), a TV with a Chromecast plugged into an HDMI port, and both devices on the same Wi-Fi network. The Chromecast itself must be powered on and set up already — if you haven't done that yet, follow the setup guide that came with it or the Chromecast app on your phone.

Key Takeaways

  • Google Cast works by sending content from your phone or computer to the Chromecast, not by mirroring your screen, so your device can stay locked or do other things while you watch.
  • Both your casting device and your TV with Chromecast must be connected to the same Wi-Fi network for casting to work.
  • Most apps that support casting (YouTube, Netflix, Spotify, Google Photos) show a cast icon that looks like a rectangle with curved lines in the corner — tap it and pick your TV.
  • If you don't see the cast icon in an app, that app does not support casting, but you can mirror your entire screen instead through your device's settings.
  • Casting stops when you close the app or manually stop playback on the TV, and your phone does not have to stay unlocked while content plays.

Casting from Apps That Support It

Most streaming apps — YouTube, Netflix, Disney+, Spotify, Google Photos, and many others — have built-in cast support. When you open one of these apps and start playing something, look for the cast icon, which looks like a small rectangle with three curved lines in the bottom right corner. Tap it.

A menu will pop up showing all the Chromecast devices on your Wi-Fi network. Tap the name of the TV you want to cast to. The content will start playing on your TV within a few seconds, and you'll see a small cast indicator on your phone showing that something is playing on that device. You can now lock your phone, open other apps, or set it down — the content keeps playing on the TV.

To stop casting, tap the cast icon again and select "Stop casting," or just close the app. The TV will go back to whatever it was showing before. Some apps let you pause, rewind, or skip forward from your phone while content plays on the TV — the controls stay available even if your phone is locked.

Casting Your Entire Screen or Window

If an app doesn't have a cast icon, or if you want to show your phone's home screen or a specific window from your computer on the TV, you can mirror your entire screen instead. This is different from casting an individual video — your whole screen appears on the TV, and everything you do on your device shows up there too.

On an Android phone, swipe down from the top twice to open the full quick settings menu, then look for "Cast" or "Screen cast." Tap it, pick your TV, and your screen will appear on the TV. Everything you do — opening apps, typing, scrolling — shows up on the big screen. To stop, tap the cast notification and select "Stop."

On an iPhone or iPad, swipe down from the top right corner to open Control Center, tap "Screen Mirroring," pick your Chromecast, and your screen appears on the TV. On a Mac, click the Control Center icon in the top right, select "Screen Mirroring," and pick your device. On a Windows PC, press Windows key + K to open the Quick Settings panel, select "Cast to a device," and pick your Chromecast.

Troubleshooting When Cast Doesn't Appear

If you don't see the cast icon in an app, or if the Chromecast doesn't show up in your device list, start by checking that both devices are on the same Wi-Fi network. Open your phone's Wi-Fi settings and your Chromecast settings (usually in the Chromecast app) and confirm they're connected to the same network name. If one device is on a guest network and the other is on the main network, they won't see each other.

Next, restart both devices. Unplug the Chromecast for 10 seconds, plug it back in, and wait for the light to stop blinking. Then restart your phone or computer. Open the app again and look for the cast icon. If it still doesn't appear, the app may not support casting — try mirroring your screen instead, or check the app's help section to confirm cast is available in your region or subscription tier.

If the cast icon appears but the TV doesn't show up in the device list, make sure the Chromecast is powered on (check the light on the device itself) and that your Wi-Fi router is working. If your Wi-Fi has a 5 GHz and 2.4 GHz band, try connecting your phone to the 2.4 GHz band, as some Chromecast devices work better on that frequency. Restart your Wi-Fi router if nothing else works.

What Happens to Your Phone While You're Casting

When you cast a video or song to your TV, your phone is just sending instructions to the Chromecast — it's not streaming the video through your phone to the TV. This means you can lock your phone, open other apps, or even turn off the screen and the content keeps playing on the TV without interruption. Your phone's battery drains much more slowly than it would if you were mirroring your screen.

However, if you close the app that's casting, or if your phone loses Wi-Fi connection, playback on the TV will stop. If you're casting from a web browser (like YouTube on Chrome), closing the browser tab will also stop playback. Some apps let you control playback from your phone even after you've locked it — you can pause, skip, or adjust volume without waking the screen.

Casting Music and Photos

Casting music works the same way as video. Open Spotify, YouTube Music, Google Play Music, or another music app, tap the cast icon, pick your TV or a speaker with Chromecast built in, and the music plays through that device's speakers. You can control volume and skip tracks from your phone, and the app usually shows what's playing on the TV screen as well.

For photos, open Google Photos, select a photo or album, tap the cast icon, and the photos appear on your TV. You can swipe through them on your phone and they'll advance on the TV. This is useful for showing family photos on a big screen without having to gather around a phone. Some photo apps also let you start a slideshow that plays automatically on the TV while you control the pace from your phone.

Casting from a Web Browser

If you're watching something in a web browser on your computer, you can cast the tab (or your entire screen) to a Chromecast. On Chrome, click the three-dot menu in the top right, select "Cast," pick your device, and choose whether to cast just the current tab or your entire screen. The video will play on your TV, and you can keep using your computer for other things.

On Firefox, you can cast to Chromecast by installing an extension, but native support is limited. Safari on Mac does not have built-in Chromecast support, though some apps like YouTube have their own cast buttons. If you're using a browser that doesn't support casting, try opening the video in the app version instead, or mirror your entire screen.

Frequently Asked Questions

Do I need to keep my phone unlocked while casting?

No. Once you've started casting, you can lock your phone, put it in your pocket, or even turn off the screen. The content continues playing on the TV. Your phone only needs to stay connected to Wi-Fi — it doesn't need to stay awake or unlocked.

Can multiple people cast to the same TV at the same time?

No. Only one device can cast to a Chromecast at a time. If someone else tries to cast while you're already casting, their device will take over and your content will stop. Some Chromecast devices have a guest mode that lets visitors cast without being on your home Wi-Fi, but only one person can cast at a time.

What's the difference between casting and screen mirroring?

Casting sends specific content (a video, song, or photo) from an app directly to the TV. Screen mirroring sends your entire screen, so everything you do on your device appears on the TV. Casting uses less battery and lets your phone do other things; mirroring shows everything but drains your battery faster.

Why does casting stop when I close the app?

When you close the app, the Chromecast loses the instruction to keep playing. The content isn't stored on the Chromecast itself — it's being fetched from the internet or your device based on commands from the app. Closing the app stops those commands, so playback stops.

Can I cast if I'm not on my home Wi-Fi?

No. Your phone and the Chromecast must be on the same Wi-Fi network. If you're away from home, you can't cast to a Chromecast at your house. Some Chromecast devices support guest mode, which lets you cast over the internet, but this feature must be set up ahead of time in the Chromecast app.