Borderless Window Manager: force any game windowed or borderless, on the monitor you want

One key

Press Ctrl+Alt+B while a game is in front and it goes borderless: the title bar and frame disappear, the picture fills the monitor, and alt-tab is instant. It works in games that were never designed for it. Undo it any time from History.

“Fill the monitor” is only the default:

• Half an ultrawide. Borderless into the left or right half, with a black backdrop behind so the desktop never shows through.
• The game’s own aspect ratio. A 4:3 or 16:10 game stays that shape, centred, with clean black bars.
• Any monitor. The one you’re on, the one you launched from, or the one you name.

Click your second monitor without the game minimizing

A borderless window is still a window. Move to a browser, a chat or a guide on the other screen and back again; the game stays exactly where it is, full size, never minimized. Works fine on one monitor too.

A window of its own

For a game that has no windowed mode at all. Pick it on the Windowed page, or send it there from the Games page, and from then on it runs inside a window of the app’s: a title bar, edges to drag, a minimize button. Choose where it opens (centred, a corner, or where you last put it) and how big: as placed, as large as fits, or an exact size such as 1280 × 720. A game that applies its own resolution a second after it starts can be given a moment before it’s placed.

Borderless Window Manager · Windowed

Games with no windowed option

The app knows how the common engines store their display settings: Unity, Unreal Engine 3, 4 and 5, Godot, GameMaker, RPG Maker, Ren’Py, Source and Source 2, id Tech, CryEngine, and the NW.js and Electron runtimes. It changes them the way the game itself would, through the game’s own configuration file or registry value, while the game is closed, with a backup. Where an engine only takes a launch option, the app shows you the exact text to paste into the game’s Steam launch options.

The Steam store page carries this disclosure, repeated here word for word:

To make a game run windowed, this app edits that game’s configuration file or registry value only when you ask it to, only while the game is closed, always with a backup and an Undo button in History. It never modifies game executables and never injects code.

Every window where you want it

Capture a rule from any window in two clicks: which monitor it opens on, how big, borderless or not, always on top, first window or every window of that app. Position memory brings windows back after sleep, a monitor unplugging or a docking station, without you doing anything.

Tab groups

Put Discord, a browser and a guide into one window as tabs, listed down its side. The group moves, resizes and minimizes as one, and it can sit beside the game in the other half of the monitor. Or dock a thin strip to the edge you choose (left, right, top or bottom) and share that area of the monitor instead. Click a tab or press a hotkey and that window comes to the front. Every tab stays an ordinary window, in Alt-Tab and on the taskbar, and nothing is ever drawn over a game.

Borderless Window Manager · Tab groups

Hotkeys, History and a clean exit

• Hotkeys: every action can have a key combination: borderless, left half, keep aspect, always on top, the next tab, a jump straight to one window. Set one by pressing it on the Hotkeys page; if something else already uses that combination, the app says what.
• History and undo: everything the app changes is listed in one place, with the original value beside it. Undo a single change, or undo everything.
• Prepare for uninstall (Settings) puts everything back before you remove the app: window borders, game settings, registry values, the display mode and the startup entry, with a checklist of what it restored.

What it never does

• Never asks for administrator. It runs as a standard user, always.
• Never puts code inside a game. No injection, no in-game overlay. On Plasma, its one piece outside the app is a small script that runs in KWin, the desktop’s window manager, and is removed when the app exits.
• Never goes online. No accounts, no telemetry, no crash reports. Everything it records stays in its data folder on your PC. See the privacy statement.
• No DLC. Every feature is included.

Requirements and platform notes

• Windows 10 or 11, 64-bit. Nothing else to install: no .NET runtime needed. About 200 MB of disk.
• SteamOS, Desktop Mode, and other KDE Plasma 6 desktops. Proton games are managed like any other window. On Plasma, a Proton game on the Windowed page can be given its own display of the window’s size, so it renders at exactly that size and never leaves the window. There is no Steam Deck compatibility rating.
• Runs without Steam open, and updates through Steam.
• Settings and history live in %APPDATA%\BorderlessWindowManager on Windows and ~/.config/BorderlessWindowManager on SteamOS and Linux. Settings has an “Open data folder” button.
• Bugs and requests go to the app’s Steam Community forum; the Feedback page in the app links to it, with the line to paste (product, version, OS).

Questions people ask before buying