About Spanpaper X-Leg Calculator

Spanpaper

Create wallpapers that span perfectly across multiple monitors with different resolutions, scaling settings, and physical sizes.

Example on my Setup:

Original wallpaper
Original Image
Transformed output
Transformed by spanpaper
Setup result
Applied on my setup (I Need to buy monitors with matching colors...)
Example Image from Jonny Gios on Unsplash
KDE on X11 mode selected.

Configuration Guide

Configure Monitors from LEFT to RIGHT

Resolution
Your monitor's resolution. Choose a preset or enter pixels manually.
Scaling Factor
The scaling factor you set in system settings (e.g., 100% = 1.0, 150% = 1.5).
Size (inches)
The physical size of your monitor in inches (diagonal measurement).
Aspect Width and Height
The aspect ratio of your monitor (e.g., 16 and 9 for a 16:9 display).
Bottom Offset
The physical offset to the lowest monitor in inches. Set the lowest monitor to 0, and others to how much higher their bottoms are.
Gap after monitor
The size of the gap between this monitor and the next one in inches.
xrandr Output (optional)

Use this field only if your monitors are not bottom-aligned in your system settings. See the images below to determine if you need it.

Monitors bottom-aligned

Bottom-aligned: You don't need xrandr output

Monitors not bottom-aligned

Not bottom-aligned: You need xrandr output

If you need it: Open your terminal, run xrandr, and paste the entire output into the field below all monitors. The system will automatically calculate the pixel offsets needed to align your wallpaper correctly.

Applying the Wallpaper

KDE Plasma Setup

A separate wallpaper image is generated for each monitor. To apply:

  1. Right-click your desktop and select Configure Desktop and Wallpaper
  2. Select the monitor you want to configure
  3. Set the wallpaper to the corresponding generated image (monitor_1.png, monitor_2.png, etc.)
  4. Set Positioning to Scaled (Keep Proportions)
  5. Repeat for each monitor

About

Everything happens in your browser, your images never leave your device. The setups are saved locally in your browser.

If you are intrested in how this works, check out the github link down below. Its a python script that does the exact same the Linux X11 varaints do. I plan to add the windows version there as well sometime..., windows handles scaling a bit different so the python script wont work on windows yet.

View on GitHub

Configure Your Setup

Configure your monitors from left to right. Start with your leftmost monitor and add additional monitors in the order they appear on your desk.

Monitor 1

Monitor 2

See the Configuration Guide on the left to determine if you need this field. If your monitors are not bottom-aligned in your system settings, paste the complete output of the xrandr command here.
Raw Wallpapers
Drag and drop your images here or click to select