How to Launch Minecraft Directly in Borderless Mode Using the Startup Flag

Add the Flag to Your Launcher

Cubes Without Borders adds a startup argument, --borderless, that forces the game to open in borderless fullscreen without you touching Video Settings. To use it, open your launcher's profile or installation editor and find the JVM arguments or Game arguments field (the exact label depends on your launcher).

Append the flag to the existing arguments, separated by a space:

`

--borderless

`

Save the profile and launch the game. Minecraft should start already filling the screen in borderless mode.

When to Use This

This is handy if you switch between multiple profiles or want a dedicated shortcut that always opens borderless. It also helps if you frequently reset your options or share a profile with someone who prefers windowed mode — the flag overrides the saved setting at launch.

Troubleshooting

If the game ignores the flag, double-check you added it as a separate argument and not glued onto another one. Also confirm the profile you edited is the one you actually launched. Removing the flag returns control to whatever the Video Settings toggle is set to.