Real Minecraft Java worlds, from your browser

A browser on its own cannot run a Minecraft Java server. The Helper can: it is a free Windows app, MC Server Helper, that starts genuine servers on your own machine, and the site connects to them. You install it once from the Microsoft Store and after that it starts with Windows by itself.

What it actually does

When you choose to create a real Java world, the page does not simulate anything: it asks the Helper to start an actual server (vanilla or Paper) on your PC, and then connects to it. The world that comes out of it is a standard Java world, with its own generation, its own mechanics and ordinary save files.

It lives in the system tray, next to the clock: it starts by itself when you turn the PC on, and the site finds it on its own. Its window lets you see and manage your worlds, but you do not need to open it to play.

You do not need to install Java: the Helper downloads the version each world needs.

Installing, just the once

1. Open MC Server Helper in the Microsoft Store and click Get. It is free.
2. Open it once from the Start menu. From then on it starts with Windows by itself.
3. Go back to the site: it finds it on its own.

Because it comes from the Store, Windows shows no blue SmartScreen screen and asks for no administrator rights, and updates arrive through the Store like any other app's.

If you had the old Helper (Instalar.cmd)

Uninstall it first from Start menu → Webcraft → “Desinstalar Asistente Webcraft” and, when it asks, say yes to keeping your worlds. Then install MC Server Helper: it uses the same worlds folder, so you will find them all.

Where your worlds live

In %LOCALAPPDATA%\Webcraft\mundos-java: paste it into the Explorer address bar. They sit outside the app on purpose, so uninstalling or reinstalling it does not take them with it. Since they are ordinary server folders, you can copy them for a backup, or move them somewhere else.

How you use it

You go to the site, choose the real Java server and create your world; the page talks to the Helper by itself, which listens on port 8080 on your machine.

If something is not working

• If the site does not find it, open it from the Start menu (MC Server Helper) or press “Open the Assistant” on the site itself.
• If your browser asks about local network access, allow it: that is how the site talks to the Helper.
• If it will not start, the usual reason is that another program is using port 8080.

Uninstalling

Like any app: Settings → Apps → MC Server Helper → Uninstall. Your worlds stay in %LOCALAPPDATA%\Webcraft\mundos-java.