External Display BrowserYouTube5 min read

How to Watch YouTube Full Screen on a TV or Monitor From Your iPhone or iPad

You have a TV, an iPhone and a cable, and you want the video to fill the screen, the whole screen, not a phone-shaped rectangle in the middle of it, without ads. That's a five-minute setup with XeOS, and this guide walks through all of it: signing in, going full screen, and the built-in ad blocker that makes the difference between "watchable" and "actually good".

If your display isn't connected yet, do the setup guide first.

Why mirroring doesn't cut it

iOS screen mirroring sends the TV a copy of your phone's screen. A phone is roughly 19.5:9; a TV is 16:9. The TV pads out the difference with black bars down both sides, and then YouTube's own video sits inside that, so you end up watching a small picture surrounded by two layers of nothing. No amount of tapping the full-screen button in YouTube fixes it, because the problem is one level up.

XeOS doesn't mirror. It renders a desktop at the display's own resolution, so a full-screen video is genuinely full screen.

Step 1, Sign in to YouTube

Open the Browser from the dock and go to youtube.com. Sign in with your Google account as you would on a computer, you get the desktop site, your subscriptions, your history, your Watch Later.

A YouTube video playing inside the XeOS browser window, with the tab strip, address bar and bookmarks bar above it. — A full browser: tabs, address bar, bookmarks bar, downloads, reading list, and YouTube behaving like it does on a computer.

Two things make signing in much less painful:

Import your passwords from Safari, Chrome, Firefox or Edge, see the import guide. Then logging in is a tap.
Your session persists. XeOS keeps site cookies and storage across restarts, so you sign in once, not every time you plug in.

If Google's sign-in page won't accept a click on something, a consent box, an embedded frame, that's the iOS engine limitation described in Device Layout Mode. Tap the grey button, do that one step on the phone's screen, and come straight back.

Step 2, Turn on ad blocking

XeOS ships with an ad blocker built from EasyList and uBlock filter lists, compiled into the browser engine itself. It is on by default, so there's usually nothing to do, but it's worth knowing where the switch is.

Click the ⋯ button at the right of the toolbar:

The browser options menu open over a playing YouTube video, showing Block Ads and Block Ads on This Site both ticked. — Block Ads applies everywhere; Block Ads on This Site lets you make an exception for one site.

Block Ads, the global switch. Blocks ads and trackers on all sites, including YouTube video ads. The page reloads when you change it.
Block Ads on This Site, turn blocking off for one site only, if a site you rely on misbehaves without its ads.

On YouTube specifically, XeOS also handles skippable ads: when the skip button appears it is pressed for you, so an unattended screen doesn't sit on an ad countdown forever.

Step 3, Go full screen

There are two full screens in play, and it's worth understanding both.

YouTube's own full-screen button

The button in the video player's bottom-right corner works exactly as it does on a computer, the video expands to fill the browser's page area. XeOS handles this properly even when a site runs its video inside an embedded frame, which is where a lot of mobile browsers fall over.

The window's green button

For the cleanest result, put the window full screen too. Click the green button in the top-left corner:

The four window buttons, with the green full-screen button third from the left. — Green, the window loses its title bar, tabs and toolbar entirely.

Now the browser chrome, the dock and the status overlay are all gone, YouTube's player fills the browser, and the browser fills the display. That's every pixel of your TV showing video.

A YouTube video filling an entire 16:9 external display, with the player's own controls and progress bar along the bottom and no browser chrome anywhere. — YouTube's player filling the whole display, no title bar, no tabs, no dock, no bars.

The same video full screen with the player controls faded away, showing nothing but the picture edge to edge. — A few seconds later the controls fade and there is nothing on screen but the video.

To come back, move the pointer to the top edge of the screen; the title bar slides down and the green button takes you out.

Step 4, Get the sound right

Over HDMI, audio travels down the same cable as the picture, so the TV's speakers play it. Nothing to configure. Over AirPlay, sound follows the AirPlay target. If you'd rather hear it through a Bluetooth speaker or headphones, connect them in iOS as usual, XeOS mixes with whatever iOS is routing.

Making it a one-tap experience

If watching YouTube on the big screen becomes a habit, install it as its own dock app: open YouTube, then ⋯ › Add Site to Dock. It gets a proper icon in the dock and opens in its own window, so you skip the browser entirely.

The XeOS dock with app icons along the bottom of the screen. — Sites you add to the dock sit alongside the built-in apps.

You can also detach a tab into its own floating window, which is handy when you want a video playing in one window while you work in another.

Useful extras while you watch

Zoom, Cmd + and Cmd − adjust page zoom per site, and it's remembered. Handy for reading comments from the sofa.
Reading mode, Cmd Shift R strips a page down to its text. Not for video, but excellent for the article you opened next.
Reading list, save a video page to watch later from the ⋯ menu.
Downloads, the download button in the toolbar keeps a real download list with progress and speeds.

XeOS: External Display Browser turns an iPhone or iPad into a full desktop on any monitor, TV or projector.

Download XeOS on the App Store

Common questions

Does the ad blocker work on YouTube video ads?

Yes. Blocking is compiled into the browser engine from EasyList and uBlock filter lists, and skippable ads are skipped for you when they do appear.

Does this work with other video sites?

Yes. Anything with a website plays the same way, the green button takes it full screen and the picture fills the panel.

Do I need to sign in every time?

No. Sessions survive restarts, cookies and site storage are preserved deliberately, so you stay signed in.

Can I use the phone as a remote while it plays?

Yes. With no mouse connected, the phone's screen is a trackpad, so you can pause and scrub without touching the TV.

Why is there still a black border on my TV?

That's usually the TV's own overscan or picture-size setting rather than the app. Set the TV's picture size to "Just Scan", "Screen Fit" or "1:1", and check the resolution in Settings › Display matches what the TV reports.