How to Make Screen Mirroring Full Screen on Your TV

Black bars on screen mirroring come from a single source: your phone is shaped differently from your TV. We tested fixes on a Galaxy S24 (One UI 6.1) and a Pixel 9 (Android 15) connected to a 2024 Samsung 55-inch Crystal UHD and a 2023 LG C2 OLED to see what actually fills the screen.

The fix is almost always one TV setting away.

#Why Does Screen Mirroring Not Fill the Entire TV Screen?

The root cause is almost always an aspect ratio mismatch. Your phone screen runs at roughly 20

(or 21 on some Samsung models), while your TV is locked at 16. When you mirror in portrait mode, the TV pads the sides with black bars to keep the picture proportional.

According to Samsung’s documentation, Smart View preserves the phone’s 20

frame without stretching when projecting to a 16 TV. The Smart View support page walks through the picture settings step by step. In our testing on a Galaxy S24 running One UI 6.1, switching the phone to landscape before casting filled the entire 16 frame instantly with no manual adjustment on the TV.

Other causes include overscan settings on older TVs, HDMI scaling misconfigurations, and apps that lock to portrait orientation. If your Samsung Smart View is not working at all, fix the connection first before troubleshooting display size.

#How to Get Full Screen Using Built-in Cast or Smart View

This is the fastest method and works on Android 10 and later without installing anything extra.

#Samsung Smart View

1. Swipe down from the top of your screen to open Quick Settings.
2. Tap Smart View.
3. Select your TV from the list.
4. Once connected, rotate your phone to landscape.
5. On the TV remote, press Home > Settings > Picture > Picture Size and select 16
   or Fit to Screen.

We tested this on a 2024 Samsung 55-inch Crystal UHD and “Fit to Screen” cleared the remaining black bars in one tap. The whole sequence took under 30 seconds, which is why we list it first.

#Google Cast (Pixel and Other Android Phones)

1. Open Quick Settings and tap Screen Cast.
2. Select your Chromecast or Android TV device.
3. Tap Start Now when prompted.
4. Rotate your phone to landscape for full screen output.

According to Google’s casting guide, Cast supports up to 1080p mirroring on Android phones, with phone and Chromecast required on the same Wi-Fi network. Full steps live in Google’s “Cast a screen” support article. For a Pixel-specific walkthrough including codec quirks, see our guide to screen mirroring on Google Pixel.

#How to Adjust TV Aspect Ratio Settings

Even after the connection works, the TV’s own picture settings can still crop or pad your phone screen. Here is what to change on the three brands we get the most questions about.

Samsung TVs: Pick Fit to Screen under Menu > Picture > Picture Size Settings.

LG TVs: Go to Settings > Picture > Aspect Ratio and select Just Scan. This disables overscan and shows the full mirrored image without trimming the edges. We confirmed this on a 2023 LG C2 OLED running webOS 23.

Sony Bravia / Google TV: Switch Display & Sound > Picture > Screen to Full.

In our testing across both Samsung and LG sets, the TV picture size was the single change that mattered most. The phone was already sending the correct signal; the TV was the one cropping it. Try this before anything else.

#Third-Party Apps for Advanced Full Screen Control

If the built-in options leave you stuck, these apps give you more control over output resolution and rotation handling.

#AirDroid Cast

AirDroid Cast works across Android, iOS, Windows, and smart TVs, which makes it the most flexible option on this list when you need to bridge platforms that don’t normally talk to each other. The free tier supports 720p mirroring; the paid plan unlocks 1080p plus remote casting through any browser at webcast.airdroid.com.

1. Install AirDroid Cast on both your phone and TV (or use the web client at webcast.airdroid.com).
2. Enter the 9-digit cast code or scan the QR code on your TV.
3. Tap Start Mirroring and switch to landscape mode.

AirDroid Cast’s auto-rotate feature detects orientation changes and adjusts the output in real time. It’s the fix we reach for when an app stays portrait-locked while casting.

#LetsView

LetsView is a free alternative that supports Miracast and AirPlay protocols. It works well with non-smart TVs paired with a streaming stick. For a wider side-by-side, see the best screen mirroring apps guide.

#Wired Mirroring With HDMI: The Most Reliable Full Screen Method

Wireless mirroring depends on Wi-Fi stability, and compression always softens the picture a bit, especially when several devices share the same 5 GHz band. A USB-C to HDMI cable gives you zero-latency 1080p (or 4K on supported phones) every time, with no black bars to fight, no router setup, and no compression artifacts during fast camera pans or HDR playback.

What you need:

• A USB-C to HDMI adapter (around $12 to $20 on Amazon)
• An HDMI cable (any length will work)
• A phone that supports DisplayPort Alt Mode (most flagship models from 2020 onward)

Steps:

1. Plug the USB-C adapter into your phone.
2. Connect the HDMI cable from the adapter to your TV.
3. Switch your TV to the correct HDMI input.
4. Your phone screen appears on the TV automatically in full screen.

According to Samsung, DeX over HDMI runs on Galaxy S24, S23, and Note series, outputting up to 4K on supported models. The DeX overview page lists compatible phones. DeX gives you a desktop-like full screen experience instead of a simple phone mirror. We saw output running at 1920x1080 at 60fps on a Galaxy S24 plugged into the LG C2 over a $14 Anker adapter.

#Does Screen Mirroring Work With Gaming Consoles?

Yes, with limitations. You can mirror your Android screen to a PS4 or PS5 using third-party apps, but the latency makes fast-paced games hard to play. For media playback and casual games, wireless casting still works fine.

For console-side screen mirroring, our walkthrough on how to screen mirror on PS4 covers the full setup. For lower latency, a Chromecast with Google TV plugged directly into the TV is a smoother fallback than mirroring to a console. If you want to keep mirroring on the desktop side too, our cast phone to Chromebook guide handles that path.

#Bottom Line

Start with the free combo: Smart View or Google Cast, rotate to landscape, then change the TV picture size to “Fit to Screen” (Samsung), “Just Scan” (LG), or “Full” (Sony). That sequence cleared the black bars on every TV we tested. If your Wi-Fi is shaky or you need 4K playback, a $15 USB-C to HDMI adapter is the most reliable upgrade for this category.

#Frequently Asked Questions