Here's a quick guide to downloading a world from Realms on Minecraft: Java Edition.
First, start the game and select Minecraft Realms. There you'll find a list of Realms that you own or have been invited to. You can only download a world from a Realm that you own, as follows:
- Go to your Realms configuration by selecting the button with a tool symbol.
- From the Realms configuration screen, go to your World backups.
- Select the Download Latest button and follow the instructions on your screen.
The world you download will be saved with your single-player worlds. You can access downloaded worlds in single-player mode and you can upload them to a different Realm. If the world you want to upload was created in a version of Minecraft that is older than the current game version, it might not be compatible with Realms. To solve this problem, try starting the world in single-player mode, which should update it to the latest version if your device is compatible.
Downloaded worlds are also available in your saves folder located with your Minecraft files. You can learn more about where your files are stored at Where Are Minecraft Files Stored?