Help with JustBuild

Start building

Getting started and controls covers world presets, movement, flight, the block picker and undo. Try the starter-house guide for a small building project.

Save, back up or move a world

Worlds are stored in this browser, rather than an account. Read saving and sharing worlds before changing browsers, devices or site addresses. A seed repeats terrain; a world code carries your saved edits.

The game does not start

Use a current browser with JavaScript and WebGL enabled. If the game reports a graphics error, check your browser's hardware acceleration setting and restart it. Other demanding tabs and low available memory can affect play. Touch controls are available, but device performance varies.

If a visible error persists, copy its text for a bug report. Do not clear site data as a first troubleshooting step: that can delete your saved worlds.

Clipboard access is blocked

Allow clipboard access when copying or loading a world code. Loading can offer a paste prompt when reading is denied. When moving from an old address, its export page has a selectable code that you can copy manually.

Storage is unavailable or full

Private browsing and browser settings can restrict local storage. Keep any existing world-code backups. Free unrelated storage only after checking what it contains; removing JustBuild site data removes local saves.

Report a problem

Email contact@justbuild.world with your device, browser version, steps to reproduce and any visible error. A screenshot can help. Do not include a private world code unless you intend to share its contents.