Wallpaper

Your family

Pick a wallpaper, rotate them, give each monitor its own, and tune videos and the backdrop. Colours that follow the wallpaper are on Colours and themes.

Change the wallpaper

Press Ctrl+Alt+T to open the wallpaper picker. It works on the monitor you are focused on.
In SettingsQuickWallpaper, Selector opens the full picker and Choose file picks any image on your system.
The Wallhaven browser in the left sidebar (Material) searches wallhaven.cc. NSFW results need a Wallhaven API key.
iRiS: iRiS SettingsWallpaperLibrary sets the Wallpapers folder. Waffle: Waffle SettingsBackgroundWallpaper.

Rotate wallpapers

SettingsWallpaperSourceShuffle wallpapers:

Shuffle wallpapers automatically is off by default. Change every sets the interval, 30 minutes by default.
Shuffle folder (optional) picks another folder. Leave it empty to shuffle the current one.
Regenerate theme colors on shuffle is on by default. Turn it off to change the picture and keep the colours.

Wallpapers folder on the same tab sets where the picker looks. It defaults to ~/Pictures/Wallpapers.

In iRiS: iRiS SettingsWallpaperWallpaper shuffle (Shuffle wallpapers, Every, From the folder and Colours follow).

Monitors and scaling

SettingsWallpaperScreensMulti-monitor: turn on Per-monitor wallpapers, pick a monitor, then use Change wallpaper, Random, Reset to global or Apply to all.
Wallpaper scaling (same tab): Fill crops the picture to the screen, Fit shows the whole picture with bars, and Span lays one picture across every screen. Stretch, Tile and Center are there too.
Hide main wallpaper in fullscreen (Screens › Fullscreen behavior) is on by default. The overview backdrop stays.
iNiR warns you when a picture is smaller than your monitor. Hide wallpaper upscale notification (SettingsWallpaperNotifications) turns that off.
Waffle: Per-monitor wallpapers and Scaling in Waffle SettingsBackgroundWallpaper. iRiS: A wallpaper per screen and Small wallpaper notice in iRiS SettingsWallpaperLibrary, Scaling in iRiS SettingsWallpaperScaling.

Transitions and renderer

SettingsWallpaperMotionWallpaper transitions: pick a Transition style such as Fade, Wipe, Grow, Dissolve or Glitch. Random picks one at random. Waffle: Waffle SettingsBackgroundWallpaper transitions. iRiS: iRiS SettingsWallpaperTransition.
SettingsWallpaperSourceWallpaper renderer: Standard is the default. Interactive web shows a local HTML file or a web page as the wallpaper. It runs on your system’s Qt even when the shell runs on qs-rs, so it needs your distribution’s Qt 6 WebEngine and LayerShellQt packages; inir webengine only covers the Web Apps tab. In iRiS: Renderer and Takes clicks and keys in iRiS SettingsWallpaperLibrary.

Videos and GIFs

Videos can be mp4, webm, mkv, avi or mov. Pictures can be jpg, png, webp, avif, bmp, gif, tif or svg.

Play videos and GIFs as wallpaper (Screens › Wallpaper scaling) is on by default. Off shows a still frame instead.
Freeze videos and GIFs while on battery power is on by default.
Waffle: Waffle SettingsBackgroundWallpaper Effects. iRiS: Animate on the desktop in iRiS SettingsWallpaperLive wallpapers.
Effects › Wallpaper effects: Enable wallpaper blur is off by default. Blur radius (32) and Thumbnail blur strength (%) tune it, the second for videos.

Backdrop

The backdrop is a separate, blurred layer that shows while the overview is open. SettingsWallpaperEffectsBackdrop (overview):

Enable backdrop layer for overview is on by default. Use main wallpaper is on too. Turn it off to Pick backdrop wallpaper.
Backdrop blur radius (64) and Backdrop dim (%) (20) tune the look.
Hide main wallpaper (show only backdrop) is off by default.
Aurora glass effect gives glass panels colours from the wallpaper, like the sidebars.

Waffle keeps them under Waffle SettingsBackgroundBackdrop (Overview), iRiS under iRiS SettingsWallpaperOverview backdrop.