Wallpaper Engine is a Steam program that plays things on your desktop

It has never had a free tier, it runs on Windows and nothing else, and most of its wallpapers were not made by the people who published them. Search demand measured at DataForSEO for the United States puts wallpaper engine at 60,500 searches a month, behind only the two plain requests for an anime background and an anime wallpaper, and that demand resolves into four questions: what the program draws, where the wallpapers come from, what it costs to buy and to run, and which machines it runs on.

What Wallpaper Engine draws behind your icons

Wallpaper Engine draws one of four kinds of wallpaper behind your icons, and which kind you pick decides most of what it costs to run. A video wallpaper is an encoded loop, decoded frame by frame as a video player decodes a film. A live wallpaper is a video your device never stops playing, and this type is that idea with no qualifications on it. A scene wallpaper is a layered composition assembled in the program's own editor, where a still image has been cut into planes that drift with the mouse, and it is rendered live rather than played back. A web wallpaper is an HTML page rendered by an embedded browser, which is how clocks, audio visualizers and anything you can click on get made. An application wallpaper is a compiled program drawing straight to the desktop, and it is the only one of the four that is arbitrary code.

The four are not equally expensive. A video wallpaper leans on the fixed function video decoder built into the GPU, silicon that does nothing else and is idle most of the time. A scene, web or application wallpaper leans on the same 3D pipeline your games use. That distinction is most of the performance question, which has a page of its own.

Where the wallpapers come from, and who owns them

The wallpapers come from the Steam Workshop, which is a user upload system, so the rights on any given item are whatever the uploader says they are. Frequently the uploader did not make the art. A still frame pulled from an episode, a character model exported from a game, a piece of fan art reposted with the signature cropped off: all three are common, and none of them change who owns the picture. Finding the picture is the easy part; establishing that it is yours to use is the work, and a subscribe button is not a license.

Fan art is worth being exact about, because it is most of what the anime side of the Workshop consists of. The artist owns the drawing they made, the characters in it remain the rights holder's, and nobody can grant permission they were never given. For a wallpaper on your own screen this stays a private question. It stops being private the moment the desktop appears in a stream, a screenshot or a video thumbnail.

Setting one wallpaper across two monitors

To span a wallpaper across two monitors, give Wallpaper Engine a file as wide as both panels added together. Two 1920 x 1080 displays side by side make one canvas of 3840 x 1080. Two 2560 x 1440 displays make 5120 x 1440, the same pixel count as one 32:9 super ultrawide panel, and they will take the same files. The program will also hold a different wallpaper on each display, which is what most people want in practice, because a composition framed for 16:9 reads badly cut in half by a bezel.

Two monitors are the cheapest demonstration of the rule this site turns on. The same picture is a different file on every screen you own, and a Workshop item built for a single 1920 x 1080 display does not become a 3840 x 1080 item by being dragged across one. A scene often rescales cleanly, because it is drawn at whatever size it is asked for. A video wallpaper cannot: it has the resolution it was encoded at.

What it costs to buy, and what the free alternatives do instead

Wallpaper Engine costs money. It is a paid product on Steam, it has never been free, and this page does not quote a price, because Steam prices change and vary by region. Two open source programs cover most of the same ground for nothing: Lively Wallpaper, Windows only, and ScreenPlay, cross platform. Both play video and web wallpapers. Neither has the Workshop, and the Workshop is most of what buyers are actually paying for.

What it costs the machine while you are playing

While a game is running, Wallpaper Engine costs close to nothing, because it pauses by default whenever another application is fullscreen or maximized over it. This is why its measured frame rate cost in games is usually near zero: there is nothing to measure, because nothing is being drawn. The quality and FPS settings control what it draws in the other case, which is a desktop with a browser or a file window over part of it.

The platforms it does not run on

There is no macOS build and none has been announced, which is a flat answer with a long tail behind it. macOS fills the screen with whatever still picture you set, cropping whichever axis is proportionally longer, and it ships its own moving desktop pictures, which cannot import Workshop items. On the Steam Deck the program runs in desktop mode under Proton, unofficially, with behavior that varies by desktop environment, and a handheld at 1280 x 800 is not the display the Workshop is authored for.

Whether it is safe to install

Wallpaper Engine is safe to install in the ordinary sense: it is distributed and updated through Steam, and it does nothing to your machine that a video player and a browser do not already do. The judgment call is the Workshop. Treat the four types as four levels of trust: a video wallpaper is a media file and can only be decoded, a scene is data for the program's own renderer, a web wallpaper is somebody else's HTML and JavaScript rendered on your desktop, and an application wallpaper is a compiled executable running under your user account. Subscribing to the first is like opening a file. Subscribing to the last is like running a program a stranger sent you.

Where to go next

DEVICESYour desktop, your phone and your tablet each want a different wallpaper fileWallpaper sizes by deviceLIVE WALLPAPERA live wallpaper is a video your device never stops playingWhat it is and what it costsDEVICESmacOS fills the screen, so the sides of your picture go missingWhat macOS does to yours