If you want to get a movie or TV show up on a big screen, or beam music wirelessly to a speaker, then the Chromecast standard is one of the best ways to go about it: It couldn't be much simpler to use, it works across a host of devices and apps, and you can even use it to mirror browser tabs and Android screens.
Here's everything you need to know about the Chromecast technology developed by Google, and the Google Cast protocol that underpins it—from the steps needed to set it up, to the TV models that support it natively, and everything in between.
What is Chromecast?
Technically speaking, a Chromecast is a physical piece of hardware that you can beam video and audio to wirelessly—something like the Chromecast with Google TV, for example. However, the term is also commonly used to refer to the wireless streaming process itself, in part because a lot of devices now have Chromecast capabilities built in, with no dongle required (smart TVs from Sony, for instance, and the Google Nest Hubs).
The technology underpinning Chromecast devices is Google Cast, a protocol or set of standards developed by Google that tells devices how to communicate with each other and with the web. As long as the device you're sending content from supports Google Cast, and the device you're sending content to supports Google Cast, you've got yourself a working Chromecast setup.
Both the sending and receiving device have to be on the same wifi network, and once you tap the cast button, here's what happens: The sending device (your phone, for example) speaks to the receiving device (your TV, for example), and tells it where on the internet it can find the video you're watching, or the audio you're listening to. That file is then streamed to the receiving device from the web, though you can still control playback from the original device you started with.
So if you're using a phone and Chromecast-enabled TV together to watch a movie, the movie isn't being streamed from the phone to the television—the phone is just telling the TV which particular movie stream it needs to connect to, and where you're up to in it. That means there's no heavy lifting for your phone to do in terms of processing or transmitting, and it keeps congestion down on your network, too.
Devices with Chromecast support
When it comes to Android phones and tablets, you can mirror whatever's on the display to any Chromecast device, as well as sending content from specific apps. Just about every media app, from Pocket Casts to Prime Video to Tidal, will have a cast button somewhere in the interface you can use.
On iPhones and iPads, there's no Chromecast support for screen mirroring as there is on Android, but you will find the cast button in most media apps like Netflix and Spotify. The only exceptions are Apple's own apps, like Apple TV and Apple Music (though you can cast from Apple Music on Android).
Chromecast functionality is built right into Google Chrome as well: That means you can get the Lifehacker website, a Google Slides presentation, or anything else you've got open in a browser tab up on a bigger screen—though in this scenario, the sending and receiving devices communicate directly, so it's not really fast enough to handle video and audio streams. It works on every platform you can run Chrome on.
A lot of web apps can stream to Chromecast devices in the usual way—by sharing the specific content link for a seamless switchover—as long as you open them in Chrome. The likes of YouTube, Disney Plus, Plex, Spotify, and many others will all show a Chromecast button somewhere on the interface if they're running in the Chrome browser.
When it comes to devices that can receive Chromecast links, then obviously you've got the Chromecast dongles to start with. What's more, any TV running Android TV or Google TV will work as a Chromecast, no extra hardware required: Television sets from companies including Sony, Philips, Sharp, and Vizio are included, and Google has more information on compatible sets here.
Chromecast works with Google's range of Nest smart speakers, and if you've got a Nest smart display, then you can beam over video and Chrome browser tabs as well as audio. If you really want to, you can edit a Google Doc on your Nest Home Hub—which is impractical, but shows you how versatile the Chromecast standard can be.
How to Chromecast
If you're starting with a phone or tablet that you want to send content from, find the cast button in the app—it looks like a rectangle with three concentric arcs in the lower left corner (though Spotify goes its own way with an icon that looks like a speaker in front of a screen). It'll usually be somewhere on the "now playing" screen. You'll see the same button on a lot of video and audio web apps as well, if they're opened in Chrome.
If you're casting from the Chrome web browser, it's always best to use the cast button on the website itself, if it's showing. If not, click the three dots (top right), then choose Save and share then Cast to send whatever's in the current tab over to a Chromecast device. You can carry on using Chrome as normal, but the tab will be mirrored on the other screen.
To mirror the screen of an Android Pixel device, open Settings and choose Connected devices, Connection preferences, and Cast. On any other Android device, you can use the Google Home app to do the same job: Tap the relevant Chromecast device on the Devices tab, then choose Cast my screen.
Once Google Cast has been initiated, a list of Chromecast-compatible devices on the same wifi network appears: Just tap on the one you want to use. After a few moments, the connection is established. You can carry on using the original device, whether it's a phone app or a browser tab, to control what's happening on the other screen (so your phone can become a remote for your TV, for example).