scrcpy/doc/hid-otg.md

HID/OTG

By default, scrcpy injects input events at the Android API level. As an alternative, when connected over USB, it is possible to send HID events, so that scrcpy behaves as if it was a physical keyboard and/or mouse connected to the Android device.

A special OTG mode allows to control the device without mirroring (and without USB debugging).

Physical keyboard simulation

By default, scrcpy uses Android key or text injection. It works everywhere, but is limited to ASCII.

Instead, it can simulate a physical USB keyboard on Android to provide a better input experience (using USB HID over AOAv2): the virtual keyboard is disabled and it works for all characters and IME.

However, it only works if the device is connected via USB.

Note: On Windows, it may only work in OTG mode, not while mirroring (it is not possible to open a USB device if it is already open by another process like the adb daemon).

To enable this mode:

scrcpy --hid-keyboard
scrcpy -K   # short version

If it fails for some reason (for example because the device is not connected via USB), it automatically fallbacks to the default mode (with a log in the console). This allows using the same command line options when connected over USB and TCP/IP.

In this mode, raw key events (scancodes) are sent to the device, independently of the host key mapping. Therefore, if your keyboard layout does not match, it must be configured on the Android device, in Settings → System → Languages and input → Physical keyboard.

This settings page can be started directly:

adb shell am start -a android.settings.HARD_KEYBOARD_SETTINGS

However, the option is only available when the HID keyboard is enabled (or when a physical keyboard is connected).

Physical mouse simulation

By default, scrcpy uses Android mouse events injection with absolute coordinates. By simulating a physical mouse, a mouse pointer appears on the Android device, and relative mouse motion, clicks and scrolls are injected.

To enable this mode:

scrcpy --hid-mouse
scrcpy -M   # short version

When this mode is enabled, the computer mouse is "captured" (the mouse pointer disappears from the computer and appears on the Android device instead).

Special capture keys, either Alt or Super, toggle (disable or enable) the mouse capture. Use one of them to give the control of the mouse back to the computer.

OTG

It is possible to run scrcpy with only physical keyboard and mouse simulation (HID), as if the computer keyboard and mouse were plugged directly to the device via an OTG cable.

In this mode, adb (USB debugging) is not necessary, and mirroring is disabled.

This is similar to --hid-keyboard --hid-mouse, but without mirroring.

To enable OTG mode:

scrcpy --otg
# Pass the serial if several USB devices are available
scrcpy --otg -s 0123456789abcdef

It is possible to enable only HID keyboard or HID mouse:

scrcpy --otg --hid-keyboard              # keyboard only
scrcpy --otg --hid-mouse                 # mouse only
scrcpy --otg --hid-keyboard --hid-mouse  # keyboard and mouse
# for convenience, enable both by default
scrcpy --otg                             # keyboard and mouse

Like --hid-keyboard and --hid-mouse, it only works if the device is connected over USB.