Wallpaper Switcher gives your desktop a day set and a night set, and swaps between them on your computer's own clock. Point it at a folder you already have, tag each picture as Day or Night, and forget about it: brighter photos while you work, dark ones in the evening.
It is free and open source, under the MIT License. In this version, it's totally offline - no connections to the internet are being made. The only thing it ever touches is the folder you choose. I am thinking of additional plug-ins that will allow you to pair the app with online wallpaper hosting services.
Most of operating systems can shuffle a folder of wallpapers. None of them know what time it is. I just had this issue when working on my desktop PC, then on MacBook - and thought someone has to do it.
The apps that do solve this usually come with strings attached: an account, a subscription, a single photo service you have to take your pictures from, and a background process quietly talking to somebody's server.
WallpaperSwitcher (okay, that placeholder name might change too) does the one job and stops there. Your pictures, your folder, your machine's clock. Nothing is uploaded, nothing is downloaded, and if you uninstall it, it's gone but wallpapers are not.
| Function | Description |
|---|---|
| Day and night sets | Tag each image Day, Night, or Ignore. Files with day or night in the name are tagged for you the moment you pick the folder. |
| Your own folder | One folder, subfolders included. Random photos, a pack you bought, a shared drive - it does not care where the pictures came from. |
| Shuffle on your terms | A different picture every hour, every 6 hours, each day, or each week. Or never: leave one image in a set and it stays put. |
| You set the hours | Drag a 24-hour bar to say when day and night begin. A night that runs from 21:00 to 07:00 works fine. |
| Lives in the tray | Change wallpaper, swap day and night, or switch cadence from the tray menu without opening the window. |
| Starts with your computer | Optional start-up scenario, and it can start straight into the tray with no window at all. |
| Fits the screen properly | On Windows, choose Fill, Fit, Stretch, Center, Tile, or Span across monitors. |
| Looks like your desktop | Follows your light or dark theme automatically, on all three operating systems. |
| Method | File |
|---|---|
| Installer (easiest) | WallpaperSwitcher-<version>-win-x64-Setup.exe |
| Portable (no install) | WallpaperSwitcher-<version>-win-x64.zip |
Windows 10 or 11, 64-bit. Nothing else to install; everything it needs is inside.
The installer is per-user: it never asks for administrator rights, it adds the usual Start menu and Add/Remove Programs entries, and uninstalling cleans up after itself. The portable zip is a single file you can run from anywhere, including a USB stick.
macOS 11 or later. Download WallpaperSwitcher-<version>-osx-arm64.dmg for Apple
silicon or -osx-x64.dmg for Intel, and drag the app into Applications.
The first launch will be refused, because the app is not notarised by Apple. Run this once in Terminal and it will open normally afterwards:
xattr -dr com.apple.quarantine /Applications/WallpaperSwitcher.apptar -xzf WallpaperSwitcher-<version>-linux-x64.tar.gz
chmod +x WallpaperSwitcher
./WallpaperSwitcherlinux-arm64 is published too. Works on GNOME, KDE Plasma and XFCE, and on any
compositor with swww or feh available, it tries each in turn.
Because the app is not code-signed. Windows will say "Windows protected your
PC" (click More info → Run anyway) and macOS will say the developer
cannot be verified (use the xattr command above).
I'll probably make it easier by getting binary signing cert later on. Stay tuned.
What you get instead: every release is built in public by GitHub Actions straight from a tagged commit, and SHA-256 checksums are attached to each release so you can check that the file you downloaded is the file that was built. And if you would rather trust nothing at all, build it yourself - it is one command.
Pick your folder on Settings, then tag your pictures on Wallpapers. Clicking a tile cycles it Day → Night → Ignore, and anything left on Ignore is never used. There is no Save button - it's automatic.
Back on Settings, drag the bar to set when day and night begin, and choose how often to shuffle. That window on macOS:
Closing the window asks whether to keep running in the tray or quit properly, and can remember your answer: that row on Settings changes it back if you want to swap it.
A few decisions worth knowing about:
- The picture for a given period is fixed, not random. It is worked out from the date and the period, so restarting the app or rebooting gives you the same wallpaper back instead of a fresh shuffle.
- A "day" ends when your night starts, not at midnight. An evening that runs past midnight is still the same evening.
- It wakes up when it should. A timer fires on the next boundary, a once-a-minute check catches a machine that was asleep, and on Windows it also listens for the clock changing, the screen resolution changing, and other apps taking the wallpaper over.
- A broken picture never ends with a blank desktop. Images are checked before use, and an unusable one is skipped in favour of the next and noted in the log.
- Your tags survive. They are stored relative to the wallpaper folder, so renaming or moving it does not throw them away.
docs/design-notes.md goes into the details, including
daylight saving and the known limitations.
Does it upload my photos anywhere? No. The app makes no network connections whatsoever so far. There is no account, no server and no telemetry.
Does it need to be running? Yes: it lives in the tray and changes the wallpaper when the time comes. Turn on "Start when I sign in" and you can forget it exists.
What image formats work?
| Format | Preview thumbnail | Works as wallpaper |
|---|---|---|
.jpg .jpeg .png .bmp .gif |
Yes | Yes |
.tif .tiff |
No | Yes |
.heic .heif .webp |
.webp only |
Only with the matching Windows codec installed |
Where does it keep my settings? In plain, readable JSON:
%LOCALAPPDATA%\WallpaperSwitcher\settings.json on Windows, or
~/.local/share/WallpaperSwitcher/settings.json on macOS and Linux. Logs are
beside it and are kept for 7 days. Uninstalling leaves both alone unless you ask
for them to be removed.
Can I have more than two sets? Not in this version - may be a future feature or a contribution at some point.
Something is wrong. Open an issue
- the log folder is on the Settings page, and attaching it helps a lot.
You need the .NET 9 SDK.
git clone https://github.com/msk-one/WallpaperSwitcher.git
cd WallpaperSwitcher
dotnet build WallpaperSwitcher.sln -c Release
dotnet test WallpaperSwitcher.Tests/WallpaperSwitcher.Tests.csproj -c Release
dotnet run --project WallpaperSwitcher.DesktopTo produce the same artifacts a release does:
./scripts/publish-windows.ps1 # portable zip + Inno Setup installer./scripts/package-macos-dmg.sh osx-arm64 # .app bundle + DMG, macOS only
./scripts/publish-linux.sh linux-x64 # tarballEach target is built on its own operating system, which is exactly what
.github/workflows/release.yml does. A macOS
build produced anywhere but macOS will not run: arm64 binaries need a signature that dotnet publish only applies on a Mac.
| Project/file | Description |
|---|---|
WallpaperSwitcher.Core/ |
Scheduling, settings, and image selection. |
WallpaperSwitcher.Desktop/ |
The Avalonia app and the per-OS wallpaper adapters. |
WallpaperSwitcher.Tests/ |
Unit tests for the core. |
docs/design-notes.md |
How scheduling works and why, plus known limitations. |
Built with .NET 9 and Avalonia. The UI is written in C# not XAML: CONTRIBUTING.md explains why, and covers the pull request process.
MIT. Do what you like with it!
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