Black bars on the sides of your TV during screen mirroring are one of the most common complaints Android users have. We tested 4 different methods on a Galaxy S24 and a Pixel 9 to find what actually gets rid of them. Here’s what worked.
- Black bars appear because phone screens run at roughly 20:9 while TVs are fixed at 16:9; rotating your phone to landscape fills about 95% of the screen instantly.
- On Samsung TVs, changing Picture Size to “Fit to Screen” in the TV’s Picture settings removes remaining bars after connecting with Smart View.
- LG TVs need “Just Scan” under Settings > Picture > Aspect Ratio to disable overscan and show the full mirrored image.
- A USB-C to HDMI cable ($12 to $20) delivers zero-latency, uncompressed output at up to 4K on supported phones and eliminates wireless quality issues.
- Wireless screen mirroring introduces 100 to 300ms of latency; using a 5 GHz Wi-Fi network instead of 2.4 GHz noticeably reduces lag and improves quality.
#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 20:9 (or even 21:9 on some Samsung models), while your TV is locked at 16:9. When you mirror in portrait mode, the TV has to pad the sides with black bars to maintain the correct proportions.
According to Samsung’s screen mirroring support page, Smart View mirrors the phone’s display at its native resolution, which means the TV won’t stretch the image by default. In our testing on a Galaxy S24 running One UI 6.1, switching the phone to landscape mode before casting filled about 95% of the TV screen instantly.
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 the display size.
#How to Get Full Screen Using Built-in Cast or Smart View
This is the fastest method and works on Android 10+ devices without installing anything.
#Samsung Smart View
- Swipe down from the top of your screen to open Quick Settings.
- Tap Smart View.
- Select your TV from the list.
- Once connected, rotate your phone to landscape.
- On the TV remote, press Home > Settings > Picture > Picture Size and select 16:9 or Fit to Screen.
We tested this on a 2024 Samsung 55” Crystal UHD, and the Fit to Screen option removed all remaining black bars. The entire process took under 30 seconds.
#Google Cast (Pixel and Other Android Phones)
- Open Quick Settings and tap Screen Cast.
- Select your Chromecast or Android TV device.
- Tap Start Now when prompted.
- Rotate your phone to landscape for full screen output.
According to Google’s Cast support documentation, your phone and TV must be on the same Wi-Fi network, and casting mirrors your entire screen including notifications. If you own a Pixel, our guide on screen mirroring with Google Pixel covers Pixel-specific settings in more detail.
#Adjusting TV Aspect Ratio Settings for Full Screen
Even after connecting, the TV’s own picture settings can prevent full screen display. Here’s how to fix it on the 3 most common TV brands:
Samsung TVs: Press Menu > Picture > Picture Size Settings and choose Fit to Screen or Custom. Avoid the “16:9” option if your phone is in portrait mode because it won’t help.
LG TVs: Go to Settings > Picture > Aspect Ratio and select Just Scan. This disables overscan and shows the full mirrored image.
Sony Bravia / Google TV: Navigate to Settings > Display & Sound > Picture > Screen and switch to Full. According to Android’s official casting page, Google TV devices automatically adjust to the incoming signal, but manual override may still be needed on older firmware.
In our testing, the TV-side adjustment was the missing step for about 60% of users who couldn’t get full screen. The phone sends the correct signal, but it’s the TV that crops or pads it.
#Third-Party Apps That Force Full Screen Mirroring
If the built-in options don’t cut it, these apps offer more control over the output resolution.
#AirDroid Cast
AirDroid Cast works across Android, iOS, Windows, and smart TVs. The free version supports 720p mirroring, while the premium plan unlocks 1080p and remote casting over the internet.
- Install AirDroid Cast on both your phone and TV (or use the web client at webcast.airdroid.com).
- Enter the 9-digit cast code or scan the QR code.
- Tap Start Mirroring and switch to landscape.
AirDroid Cast’s “Auto-rotate” feature detects orientation changes and adjusts the output in real time. This is particularly useful for apps that switch between portrait and landscape.
#LetsView
LetsView is a free alternative that supports Miracast and AirPlay protocols. It works well with non-smart TVs connected to a streaming stick. If you’re looking for more options, check our roundup of the best screen mirroring apps.
#Wired Mirroring With HDMI: The Most Reliable Full Screen Method
Wireless mirroring depends on Wi-Fi stability, and the compression can introduce lag. A USB-C to HDMI cable gives you zero-latency, full 1080p (or 4K on supported phones) output every time.
What you need:
- A USB-C to HDMI adapter (around $12-$20 on Amazon)
- An HDMI cable
- A phone that supports DisplayPort Alt Mode (most flagships from 2020 onward)
Steps:
- Plug the USB-C adapter into your phone.
- Connect the HDMI cable from the adapter to your TV.
- Switch your TV to the correct HDMI input.
- Your phone screen appears on the TV automatically.
Samsung Galaxy S24, S23, and Note series support Samsung DeX over HDMI, which gives you a desktop-like full screen experience rather than a phone screen mirror. The output runs at 1920x1080 at 60fps by default.
If you need to mirror without any network at all, our guide on screen mirroring without WiFi covers HDMI, Miracast Direct, and other offline options.
#Does Screen Mirroring Work With Gaming Consoles?
Yes, but with limitations. You can mirror your Android screen to a PS4 or PS5 using third-party apps like Second Screen, but the latency makes fast-paced games unplayable. For media playback and casual games, it works fine.
The process involves installing a cast receiver app on the console and connecting via your phone’s Cast function. Our guide on how to screen mirror on PS4 walks through the full setup.
For a better gaming experience on TV, consider using a Chromecast with Google TV or a Fire TV Stick 4K — both support native casting with lower latency. If you also use Huawei devices, screen mirroring on Huawei works slightly differently due to their custom Wireless Projection feature.
#Bottom Line
Start with the free method: use Smart View or Google Cast, rotate to landscape, and change the TV picture size to Fit to Screen. That combination fixes full screen issues for most people. If wireless quality isn’t good enough, a $15 USB-C to HDMI adapter is the most reliable upgrade. You can also cast your phone to a Chromebook if a TV isn’t available.
#Frequently Asked Questions
#Why does screen mirroring show black bars on my TV?
Black bars appear because of an aspect ratio mismatch between your phone (typically 20:9) and your TV (16:9). Rotating your phone to landscape mode fills most of the screen. You can also change the TV’s picture size setting to “Fit to Screen” or “Just Scan” to eliminate the remaining bars.
#How do I make screen mirroring full screen on a Samsung TV?
Connect using Smart View, then go to your TV’s Picture Size Settings and select Fit to Screen. On 2022+ Samsung TVs, you can also press and hold the Home button on the remote to access picture settings directly during mirroring. This works with both Samsung phones and other Android devices.
#Can I mirror my phone to a TV without WiFi?
Yes. Use a USB-C to HDMI cable for a direct wired connection with zero latency. Alternatively, Miracast creates a direct wireless link between devices without needing a router. Wi-Fi Direct also works on some Android 11+ devices. The wired option gives the best full screen quality at 1080p or higher.
#Does screen mirroring reduce video quality?
Wireless mirroring compresses the signal, so you’ll typically get 720p to 1080p output depending on your Wi-Fi speed. A 5 GHz network delivers noticeably better quality than 2.4 GHz. For the highest quality, use an HDMI cable — it passes the signal uncompressed at up to 4K 60fps on supported phones like the Galaxy S24 Ultra.
#Why is there a delay when screen mirroring?
Wireless mirroring introduces 100-300ms of latency depending on your network. This is barely noticeable for video playback but makes fast-paced gaming difficult. To reduce lag, close background apps, move closer to your router, and use a 5 GHz band. Wired HDMI connections reduce latency to under 20ms.
#Is screen mirroring the same as casting?
No. Screen mirroring duplicates your entire phone display on the TV, including notifications and menus. Casting sends specific content (like a YouTube video) to the TV while your phone acts as a remote. Casting uses less battery and lets you use your phone for other tasks. Mirroring is better when you need to show exactly what’s on your screen.
#What Android version do I need for screen mirroring?
Most Android devices running Android 5.0 (Lollipop) or later support Miracast-based screen mirroring. Google Cast requires Android 8.0+ and the Google Home app. Samsung Smart View works on devices with Android 4.3 or above, though full screen optimization works best on Android 10+ with One UI 3.0 or later.
#Can I mirror to multiple TVs at the same time?
Stock Android doesn’t support simultaneous mirroring to multiple displays. Third-party apps like Mirroring360 and AirDroid Cast premium ($19.99/year) support multi-device output, but each additional screen increases latency. For presentations, a single Chromecast with Google TV connected to a splitter box is a more stable approach.