USBCam — Use your Android phone as a USB webcam for PC / OBS

100% free & open source (GPL-3.0). No ads, no account, no internet required — everything goes over the USB cable.

⬇️ Download (Windows & Android)

One click — these links always point to the newest release:

Platform	Download	Requirements
🪟 Windows app	Download USBCam.exe	Windows 10 or 11 (64-bit) — run it, no install
📱 Android app	Download usbcam.apk	Android 8+ — install directly (allow "unknown apps")

All releases: Releases page

What is this?

Two tiny apps that turn your Android phone into a webcam source for your PC:

• The Android app captures the camera and sends JPEG frames over the USB cable.

• The Windows app shows the live image in a clean, frameless "video only" window — perfect for OBS Window Capture (like Windowed Projector, but with full control over size and position).

• The window is just the camera image: no menu bar, no icons, no borders.

• Frameless, freely resizable (down to 160×90, up to fullscreen).

• Drag to move, drag edges/corners to resize.

• All controls on right-click: Always on top, Mirror, Flip vertical, Fullscreen, vcam, Close.

• Image always centered with aspect ratio preserved.

• USB only (adb reverse) — no Wi-Fi, no audio, no virtual driver needed.

• Optional virtual camera: send the image straight into Meet / Zoom / Discord as a webcam (right-click → vcam; requires the OBS Virtual Camera driver).

• Update check: the Android app tells you when a new version is out (with a Download button), if the phone has internet.

Quick start

1. Connect the phone by USB (file transfer mode is fine; USB debugging must be enabled).
2. Run USBCam.exe — it finds adb itself and keeps adb reverse alive.
3. Open USBCam on the phone — streaming starts automatically.
4. In OBS: Sources → Window Capture → pick the USBCam window.

OBS tip: the window is frameless, so choose the "Window" mode and enable Client area to capture exactly the video.

Controls

Action	How
Control menu	Right-click the window
Move	Left-click drag
Resize	Drag edges/corners (min 160×90)
Fullscreen	Menu or F11, exit with Esc
Mirror (selfie)	Menu → Mirror
Virtual camera	Menu → vcam
Close	Menu → Close

The window title (taskbar / Alt-Tab) shows the status: USBCam — phone connected — 1920x1080 @ 30 fps

Android app

• The phone screen is only a control panel: front/back camera, resolution (480p up to 4K), start/stop.
• Opening the app starts streaming automatically.
• Switching resolution or camera applies instantly — the stream never stops (the service reconfigures in place). Actual 4K depends on the phone's sensor.
• A dedicated "Switch camera" button toggles front/back in one tap.
• Streams in a Foreground Service + PARTIAL_WAKE_LOCK, so it keeps running with the screen off or in background.
• Bottom of the app shows the developer contact (email + Telegram).

Remote control (no touching the phone):

adb shell am start -n com.usb.cam/.MainActivity --ei facing 1      # front camera
adb shell am start -n com.usb.cam/.MainActivity --ei facing 0      # back camera
adb shell am start -n com.usb.cam/.MainActivity --ei size_index 2  # 1080p (0..4 = 480p..4K)

Building from source

Android (no Gradle needed)

Requirements: Android SDK (platform-tools + build-tools 36 + platforms;android-36) and a JDK.

cd android
build_apk.bat        →  android\app\build\usbcam.apk
adb install -r android\app\build\usbcam.apk

Windows

python -m venv .venv
.venv\Scripts\pip install PySide6 pyvirtualcam numpy pyinstaller
.venv\Scripts\pyinstaller --noconfirm --onefile --windowed --name USBCam --distpath pc/dist --workpath build --hidden-import pyvirtualcam --hidden-import numpy pc/receiver.py

Architecture (short version)

• Transport: TCP over USB with adb reverse tcp:8420 tcp:8420. The phone is the TCP client; the PC listens on 127.0.0.1:8420. The Windows app re-establishes adb reverse every 5 seconds, so the link self-heals after cable reconnects or adb restarts.
• Protocol: every frame = 4-byte little-endian header (payload length) + payload; payload = 1 byte camera id (0=back, 1=front) + JPEG bytes.
• Low latency: the phone only ever sends the newest frame (stale frames are dropped, TCP_NODELAY); the PC re-syncs to the stream head on every reconnect, so latency never accumulates.
• Android: camera2 delivers JPEG directly (no re-encode), ImageReader with acquireLatestImage.
• Windows: PySide6; frameless window with manual drag/resize hit-testing; optional pyvirtualcam output (capped at 1920×1080 by the OBS driver).

Performance notes

• The sensor is pinned to a constant 30 fps (exact [30,30] range when the sensor offers it), so the frame rate stays stable instead of throttling in low light.
• JPEG quality scales with resolution (full quality up to 1080p, tuned down above it), so 1440p/4K keeps a usable frame rate over USB2.
• Frame rate ultimately depends on your phone's sensor and its USB chip — budget phones do less, flagships do more. USB2 links cap around 20–30 MB/s, which is the practical limit for 4K.
• Front/back and resolution switching without app restart ✓ (instant, tested with rapid consecutive switches)
• Client/server kill + reconnect → auto-recovery ✓
• Killing adb server → Windows app re-establishes reverse ✓

Troubleshooting

• Window says "no phone": check the cable; adb devices must list the phone; accept the USB debugging prompt.
• Connected but no image: open the app on the phone (streaming starts when the app opens) or use the am start command above.
• MIUI: set USBCam to "No restrictions" in Battery settings so long streams are not killed.
• Latency grew: close and reopen the window (it re-syncs to the stream head) — in practice this should not happen.

Author

• Email: workspikestudio@gmail.com
• Telegram: @spike_c

License

Copyright © 2026 workspikestudio.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License v3.0 — see the LICENSE file.

In short: you may use, study, share and modify this code, but any fork or derivative (including repackaged builds) must also be released under GPL-3.0 with full source, and must keep the original copyright notice. Selling a closed-source copy of this app is not permitted.