Turning a smartphone on Android into a full-fledged second monitor for Windows, macOS or Linux is a simpler task than it seems. All you need to do is choose the right connection method and set up synchronization to expand your workspace without purchasing an additional display. This solution is relevant for remote work, streaming, video editing, or even games, when you need control over the chat on a separate screen.

But not all methods are equally effective: somewhere you are waiting Input latency is up to 100 ms when connected wirelessly via Wi-Fi 5, and somewhere there are problems with resolution on older versions Android (below 9.0). We tested 5 working methods (including the rarely mentioned scrcpy server mode) and collected checklists for each. At the end of the article there is a comparative table on latency, supported OS and hardware requirements.

If you plan to use your smartphone for professional tasks (for example, to work in Photoshop or Premiere Pro), pay attention to wired methods - they minimize lags. For everyday tasks (viewing charts, instant messengers, documents), wireless solutions are sufficient. The main thing is to check the compatibility of your device with the selected software.

📊 Why do you want to use Android as a second monitor?
Working with documents/sheets
Games (chat, map, statistics)
Video editing/streaming
Programming/debugging
Other

1. Connection methods: wired vs wireless

The choice between wired and wireless connection depends on two factors: input delays and ease of use. Wired methods (via USB-C or USB 3.0) guarantee minimal lag (10–30 ms), but limit mobility. Wireless (by Wi-Fi or 5G) are free from cables, but can slow down with a weak signal or high load on the network.

Key differences:

  • 🔌 Wired connection: stability, low latency, but dependent on cable length. Suitable for gamers and designers.
  • 📶 Wireless connection: freedom of movement, but artifacts are possible with a weak signal. Optimal for office tasks.
  • ⚡ Hybrid method (for example, USB-C + Wi-Fi Direct): combines the advantages of both options, but requires device support.

It is important to consider and Android version: on devices older Android 7.0 modern data transfer protocols may not work (for example, Wi-Fi Direct in some applications). Check the specifications of your smartphone before setting up.

⚠️ Attention: On some devices Samsung (series Galaxy S8 and older) when using USB-C to transfer video, charging may be blocked. In this case, use USB hub with a separate port for power.

2. Top 3 applications for wireless connection

Wireless solutions are convenient, but their quality depends on the selected software. We tested 10 applications and selected the three most stable:

Spacedesk - the leader in compatibility with Windows (supports even Windows 7). It works via a local network, allows you to adjust the resolution up to 4K (subject to a powerful router). Minus - on Android requires manual configuration IP addresses server.

Duet Display - optimized for macOS i iPad, but there is a version and for Android. Paid (about $10), but offers minimal latency (up to 30 ms) and support Apple Pencil (relevant for hybrid devices like Samsung Galaxy Tab S8). The free version is limited by resolution 720p.

SplashTop Wired XDisplay - a universal solution with support Linux. The free version only works via cable, but without resolution restrictions. Plugins for Chrome and Firefox allow you to stream the browser screen directly.

  • 🎯 Spacedesk: the best choice for Windowsif you need to adjust the resolution.
  • 💰 Duet Display: paid, but the most stable for macOS and creative tasks.
  • 🐧 SplashTop: the only solution with full support Linux.

Install the application on your PC and smartphone|Connect both devices to the same Wi-Fi network (5 GHz)|Disable VPN and firewalls|Check the battery charge (minimum 50%)|Adjust the resolution in the application to the screen size-->

3. Wired connection via USB: step-by-step guide

The wired method guarantees minimal latency, but requires USB-C (or USB 3.0) and mode support OTG on the smartphone. We recommend using scrcpy open software that does not require root access and works on all versions Android from 5.0.

Instructions for Windows:

  1. Download scrcpy and unpack archive.
  2. Enable USB debugging on your smartphone (Settings → About phone → Number assembly - press 7 times, then return to Settings → System → For developers).
  3. Connect the phone to the PC with a cable and confirm access to debugging.
  4. Run scrcpy.exe from the unpacked folder The smartphone screen will be displayed on. PC.
  5. To use a smartphone as a second monitor, add the flag --display 2 (if the first monitor is already connected).

For macOS/Linux installation will be required ADB via Homebrew or apt: 

brew install scrcpy # for macOS

sudo apt install scrcpy # for Linux (Debian/Ubuntu)

⚠️ Attention: On some devices Xiaomi (for example, Redmi Note 10) when you first connect via scrcpy a black screen may appear. Solution: in the developer settings, disable the option Disable MIUI permissions.
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If the image on the smartphone screen is displayed with artifacts, reduce bitrate scrcpy command --bit-rate 5M. This will reduce the quality, but will eliminate “torn” pictures.

4. Setting the resolution and refresh rate

By default, most applications set the resolution 1920×1080 at 60 Hz, but these parameters can (and should) be adjusted. For example, for Samsung Galaxy S22 Ultra the optimal would be 1440×3200 (native resolution), but only with a wired connection - wireless protocols may not be able to handle such a load.

How to change parameters:

  • 🖥️ V Spacedesk: Settings → Display → Custom Resolution (specify values that are multiples of the native resolution of your smartphone).
  • 🔧 V scrcpy: use flags --video-bit-rate 8M (for quality) and --max-fps 30 (to save resources).
  • ⚡ V Duet Display: settings automatically adjust to the native resolution, but can be forced to be limited to 1080p for stability.

Important: with high resolution (4K) and frequency 120 Hz even a wired connection can cause lags on weak PCs (for example, with integrated graphics Intel UHD). Check performance in Task Manager (Ctrl+Shift+Esc) - if GPU load exceeds 80%, reduce resolution.

Application Max. resolution Max. FPS Latency (wire) Latency (Wi-Fi 5)
Spacedesk 3840×2160 60 15–25 ms 50–80 ms
Duet Display 2560×1440 60 (120 V Pro) 10–20 ms 40–70 ms
scrcpy Native 60 (144 with patch) 5–15 ms 30–60 ms
SplashTop 1920×1080 30 20–35 ms 70–100 ms

5. Solving common problems

Even with correct configuration, errors may occur. Here are the most common ones and how to fix them:

Problem 1: Black screen when connected via scrcpy

  • 🔌 Check the cable - it must support data transfer (not all USB-C cables are the same!).
  • 📱 Enable USB debugging and confirm access on your smartphone.
  • 🖥️ Update drivers ADB on PC via Device Manager.

Problem 2: Latency input when connected wirelessly

  • 📶 Switch to network 5 GHz (if you use 2.4 GHz).
  • 🔄 Reduce resolution up to 1280×720 and FPS up to 30.
  • 🚫 Close background applications that consume traffic (for example, torrents).

Problem 3: The application does not see the smartphone on the local network

  • 🔒 Disable the firewall (Windows Defender or third-party).
  • 🌐 Check that the PC and phone are on the same subnet (for example, both have an IP type 192.168.1.x).
  • 🔄 Reboot the router - sometimes DHCP does not provide the correct addresses.
Why on some smartphones touch input does not work?

On devices with custom firmware (for example, LineageOS) or ad blockers (like Blokada), there may be no support for transmitting touch data via ADBSolution: disable blockers or use alternative applications. like Vysor (paid, but with touch support).

6. Optimization for games and creative tasks

If you plan to use your smartphone as a second monitor for games (for example, to display a map in CS2 or chat in Twitch), pay attention to two key parameters: input lag and FPS stability. For creative tasks (drawing, editing), it is more important color rendition and resolution.

Recommendations for gamers:

  • 🎮 Use wired connection even Wi-Fi 6 gives a delay of ~40 ms, which is critical for shooters.
  • 🖥️ In NVIDIA Control Panel set Preferred refresh rate on Highest available.
  • 📱 Disable power saving on your smartphone (Settings → Battery → Performance mode).

For designers and editors:

  • 🎨 In Spacedesk activate Color Correction (in display settings) for correct color reproduction.
  • 📏 Set 100% scale (without scaling) to avoid blur.
  • 🖌️ For tablets with S-Pen (for example, Galaxy Tab S7) use Duet Display —it supports pen pressure.
⚠️ Attention: When using a smartphone as a second monitor for OBS Studio (streaming), disable hardware encoding acceleration in the app settings. Otherwise, artifacts may appear on the smartphone screen.
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For maximum gaming performance, combine a wired connection with a setup --no-audio v scrcpy - this will reduce the load on the processor and reduce latency.

7. Alternative methods: Miracast and Chrome Remote Desktop

If standard applications. are not suitable, you can use built-in protocols Miracast (for Windows 10/11) or Chrome Remote Desktop (cross-platform solution). These methods are less stable, but do not require the installation of third-party software.

Miracast (only for Windows):

  1. On a PC: click Win + P → select Connect to a wireless display.
  2. On a smartphone: turn on Wireless Display in settings (Display → Wireless display).
  3. Confirm the connection on both devices.

Cons: delay ~100 ms, no audio support.

Chrome Remote Desktop (for all OS):

  1. Install the extension Chrome Remote Desktop on your PC and smartphone.
  2. Generate an access code on your PC and enter it on your phone.
  3. In settings, select Management → Enable remote access.

Disadvantages: delay ~150 ms, cannot be used as an extension of the main screen (duplication only).

These methods are suitable for one-time tasks, but will not replace specialized applications for constant use.

FAQ: Frequent questions

Can Android be used as a second monitor for a MacBook?

Yes, but with limitations. Native support is only available in Duet Display (paid) and SplashTopFor free solutions (scrcpy) you will need manual support. setup ADB via Homebrew. On macOS Ventura and newer there may be problems with permissions - check the security settings in System settings → Privacy.

How to reduce wireless latency connection?

1. Use a router that supports Wi-Fi 6 (or at least 5 GHz).

2. Reduce the resolution to 1280×720 and FPS to 30.

3. Connect your PC to the router via cable (Ethernet), and your smartphone via Wi-Fi.

4. In scrcpy add a flag --lock-video-orientation=0 to optimize the flow.

Does this method work on Android 5.0?

Yes, but with reservations. scrcpy supports Android 5.0+, but touch input may not work on older versions. Applications like Spacedesk officially require Android 7.0, but on some devices (for example, Samsung Galaxy S6) they work through workarounds (installing an old version of APK). Check compatibility on the developer's website.

Is it possible to connect two Android devices as two monitors?

Technically yes, but it requires additional settings. B scrcpy launch two instances with different --display s (for example, --display 2 and --display 3). In Spacedesk it is enough to connect both devices to one server. Please note that the PC performance must be sufficient to process two video streams.

How to turn off the second monitor without turning off the smartphone?

Q Windows: click Win + P → select Screen only 1.

V macOS: open System settings → Monitors and turn off the unnecessary display.

V scrcpy: simple close the application window (the connection will be terminated, but the smartphone will remain connected via USB).