High DPI and scaling

Configure display scaling, dynamic resolution, smart-sizing, and multi-monitor support in FreeRDP.

Overview

FreeRDP supports several strategies for handling high-DPI displays and window resizing. The right approach depends on whether you want the remote session to adapt its resolution at runtime or whether you want the client to scale a fixed-resolution session to fit the window.

---

Build requirements

Graphics scaling (required for /smart-sizing and high-DPI bitmap scaling) requires one of:

Library	CMake flag	Notes
libswscale (FFmpeg)	-DWITH_SWSCALE=ON	Part of the FFmpeg libraries
Cairo	-DWITH_CAIRO=ON	Widely available on Linux/macOS

At least one scaling backend must be present for /smart-sizing to function. Dynamic resolution (/dynamic-resolution) does not require a scaling library because the remote session changes its own resolution rather than scaling bitmaps on the client.

Example build with swscale:

cmake -GNinja \
  -DCMAKE_BUILD_TYPE=Release \
  -DWITH_SWSCALE=ON \
  -B build -S .
cmake --build build --target install

---

Dynamic resolution

With /dynamic-resolution, FreeRDP sends a display update to the server whenever the client window is resized. The server re-renders at the new resolution — no client-side bitmap scaling takes place.

xfreerdp /dynamic-resolution /v:rdp.example.com

/dynamic-resolution and /smart-sizing are mutually exclusive. Specifying both is an error.

Under the hood, enabling /dynamic-resolution sets both FreeRDP_SupportDisplayControl and FreeRDP_DynamicResolutionUpdate. The server must support the Display Control virtual channel (available in Windows 8 / Server 2012 and newer).

---

Smart-sizing

With /smart-sizing, the remote session keeps its initial resolution and FreeRDP scales the received bitmaps to fit the client window. This works with any server version.

# Scale to fit whatever window size is used
xfreerdp /smart-sizing /v:rdp.example.com

# Scale to a specific target size (width x height)
xfreerdp /smart-sizing:1920x1080 /v:rdp.example.com

When a target size is supplied, FreeRDP scales to that fixed size regardless of the window dimensions.

---

Multi-monitor support

Span all monitors

xfreerdp /multimon /v:rdp.example.com

The /multimon flag sends the combined geometry of all connected monitors to the server. Use /multimon:force to send multimon information even if the server has not explicitly advertised support.

Select specific monitors

# Use monitors 0 and 2 (zero-indexed)
xfreerdp /monitors:0,2 /v:rdp.example.com

Up to 16 monitor IDs can be specified as a comma-separated list.

---

Window size and DPI

For a fixed session resolution without multimon:

# Set an explicit width and height
xfreerdp /w:2560 /h:1440 /v:rdp.example.com

# Set size as a percentage of the display
xfreerdp /size:50%h /v:rdp.example.com

# Full-screen mode
xfreerdp /f /v:rdp.example.com

---

Recommended configurations

HiDPI laptop (single screen)

Use dynamic resolution so the session always matches the window exactly:

xfreerdp /dynamic-resolution /f /v:rdp.example.com

Multiple monitors

Span the session across all monitors:

xfreerdp /multimon /v:rdp.example.com

Fixed resolution with scaling

Connect at 1920x1080 and scale the output to fill the window:

xfreerdp /w:1920 /h:1080 /smart-sizing /v:rdp.example.com