Worlds & Backups

Minecraft World Upload and Replacement Guide

Replace a Java, Bedrock, or PocketMine world safely by validating the archive, preserving the old world, and verifying the new world after import.

By PortalMine Operations & DocumentationReviewed July 31, 202611 min read
Minecraft World Upload and Replacement Guide editorial illustration

PortalMine owner documentation. Test important changes on a copy and keep a verified backup.

Safe rule: never replace a world while the server is running, and never delete the previous world before the new archive is validated.

1. Stop writes and preserve the current world

  1. Stop the server and wait until the status is fully offline.
  2. Download or create a backup of the active world and configuration.
  3. Record the current level-name value.
  4. Keep the backup outside the server storage until the replacement is verified.

2. Validate the archive structure

A valid world archive must contain the world data, not another download page or a launcher. The most common import failure is an extra wrapper folder.

EditionExpected markersTypical location
Javalevel.dat, region/, optional DIM-1/ and DIM1/World root
Official Bedrocklevel.dat, db/, levelname.txtWorld root inside worlds/
PocketMine-MPlevel.dat plus provider-specific world dataNamed folder inside worlds/

If the archive opens as MyWorld/MyWorld/level.dat, remove one wrapper level before importing. Do not flatten the files inside db or region.

3. Import and replace the active world

Use the World import action, choose the archive, and wait through upload, transfer, extraction, validation, and replacement. For a large file, 100% browser upload is not the final stage. PortalMine must still verify the server-side file and find the world root.

UploadThe browser sends the archive.
ValidateThe server checks size and world markers.
ReplaceThe old world is moved aside before the new one is activated.

4. Edition-specific notes

Java

Keep the server version equal to or newer than the version that last saved the world. Downgrading can remove blocks, entities, or data. Modded worlds also need the same loader and required mods.

Official Bedrock

The process must preserve the LevelDB db folder. Enter the displayed UDP port when joining. A healthy console start does not guarantee a mismatched client can connect.

PocketMine and Nukkit families

World formats and feature coverage differ from the official Bedrock server. A world exported from the game may require conversion or may not preserve every block and entity.

5. Verify before deleting the backup

  • Start the server and confirm it loads the intended world name.
  • Join at spawn and inspect several known locations.
  • Test inventory, dimensions, permissions, and add-ons.
  • Read the console for world-conversion or missing-content warnings.
  • Keep the previous backup until players have tested the replacement.

Related guides