wl-mirror(1) General Commands Manual wl-mirror(1)

wl-mirror - a simple Wayland output mirror client

wl-mirror [-h,-V,-v,-c,-i,-f,-s S,-b B,-t T,-r R,-S] <output>

-h, --help

Show help message and exit.

-V, --version

Show version information and exit.

-v, --verbose --no-verbose

Enable or disable debug logging.

-c, --show-cursor --no-show-cursor

Show the cursor on the mirrored surface (enabled by default).

-i, --invert-colors --no-invert-colors

Invert colors on the mirrored surface.

-f, --freeze --unfreeze --toggle-freeze

Freeze, unfreeze, or toggle freezing of the current image on the screen.

-F, --fullscreen

Open as a fullscreen window, or make the current window fullscreen in stream mode.

--no-fullscreen

Open as a regular window (enabled by default), or exit fullscreen in stream mode.

--fullscreen-output O

Set a different output to fullscreen on (default is the current output), implies --fullscreen.

--no-fullscreen-output

Sets the target fullscreen output back to the current window output, implies --no-fullscreen.

-s f, --scaling fit

Scale to fit and if necessary add letterboxing (enabled by default).

-s c, --scaling cover

Scale to cover and if necessary crop the image.

-s e, --scaling exact

Use exact multiple scaling and if necessary add letterboxing.

-s l, --scaling linear

Use linear scaling (enabled by default).

-s n, --scaling nearest

Use nearest-neighbor scaling.

-b B, --backend B

Use a specific screen capture backend, see BACKENDS.

-t T, --transform T

Apply custom transform (rotation and flipping), see TRANSFORMS.

-r R, --region R

Capture custom screen region R, see REGIONS.

-S, --stream

Accept a stream of additional options on stdin, see STREAM MODE.

--title T

Specify a custom title T for the mirror window. This title can contain placeholders, see TITLE PLACEHOLDERS

auto

Automatically try backends in order of backend efficiency and use the first that works (enabled by default). The next backend is selected automatically when the current backend fails to capture a frame 10 times in a row.

The current fallback order is:

  • extcopy-dmabuf (if compiled with libGBM)
  • screencopy-dmabuf (if compiled with libGBM)
  • export-dmabuf
  • extcopy-shm
  • screencopy-shm

export-dmabuf

Use the wlr-export-dmabuf-unstable-v1 protocol to capture outputs (requires wlroots). This backend keeps the image data on the GPU and does not need expensive copies to the CPU and back.

screencopy-dmabuf

Use the wlr-screencopy-unstable-v1 protocol to capture outputs (requires wlroots) This backend keeps the image data on the GPU and does not need expensive copies to the CPU and back. This backend requires wl-mirror to be compiled with support for allocating DMA-BUFs using libGBM.

screencopy-shm

Use the wlr-screencopy-unstable-v1 protocol to capture outputs (requires wlroots) This backend passes the image data via shared memory on the CPU, but may have better compatibility with complex GPU driver configurations (e.g., multi GPU).

screencopy

Automatically tries screencopy-dmabuf or screencopy-shm and uses the first one that works. Fallback works the same as with auto.

extcopy-dmabuf

Use the ext-image-copy-capture-v1 protocol to capture outputs This backend keeps the image data on the GPU and does not need expensive copies to the CPU and back. This backend requires wl-mirror to be compiled with support for allocating DMA-BUFs using libGBM.

extcopy-shm

Use the ext-image-copy-capture-v1 protocol to capture outputs This backend passes the image data via shared memory on the CPU, but may have better compatibility with complex GPU driver configurations (e.g., multi GPU).

extcopy

Automatically tries extcopy-dmabuf or extcopy-shm and uses the first one that works. Fallback works the same as with auto.

Transforms are specified as a dash-separated list of flips followed by a rotation amount. Flips are applied before rotations, both flips and rotations are optional. Custom transformations are applied after adjusting for the wayland output transform, so that if no custom transformations are applied, the mirrored surface is displayed right-side-up.

normal

No transformation (default transformation).

flipX, flipY

Flip the X or Y coordinate of the image, i.e. flipX means the mirrored surface has left and right swapped.

0cw, 90cw, 180cw, 270cw

Apply a clockwise rotation.

0ccw, 90ccw, 180ccw, 270ccw

Apply a counter-clockwise rotation.

The following transformation options are provided for compatibility with sway-output(5) transforms:

flipped

Same as flipX.

0, 90, 180, 270

Same as 0cw, 90cw, 180cw, 270cw.

Regions are specified in the format used by the slurp(1) utility:

'x,y widthxheight [output]'

In slurp(1) syntax, this would be specified as follows (the last part with %o is optional):

'%x,%y %wx%h %o'

When processing the region option, the region is translated into output coordinates, so when the output moves, the captured region moves with it. When a region is specified, the output positional argument is optional.

In stream mode, wl-mirror interprets lines on stdin as additional command line options.

  • Arguments can be quoted with single or double quotes, but every argument must be fully quoted.
  • Unquoted arguments are split on whitespace.
  • No escape sequences are implemented.

Option lines on stdin are processed asynchronously, and can override all options and the captured output. Stream mode is used by wl-present(1) to add interactive controls to wl-mirror.

The title string supports the following placeholders:

  • {width}, {height}: size of the mirrored area
  • {x}, {y}: offsets on the screen
  • {target_width}, {target_height}, {target_output}: info about the mirrored device

A few perhaps useful examples:

--title 'Wayland Mirror Output {target_output}'

--title '{target_output}:{width}x{height}+{x}+{y}'

--title 'resize set {width} {height} move position {x} {y}'

Maintained by Ferdinand Bachmann <ferdinand.bachmann@yrlf.at>. More information on wl-mirror can be found at https://github.com/Ferdi265/wl-mirror.

wl-present(1) slurp(1) sway-output(5)

2026-02-10