Update Old World

Keep everything you built, and let the new update's biomes and caves grow in everywhere you haven't been.

Java only. This updates Minecraft Java worlds from a computer. A Bedrock world on your phone updates itself when you open it in a newer Minecraft.

Drop your world hereChoose your world

Your world folder, or a .zip of it. It never leaves this device.

folder.zip

Where is my world?

Windows %appdata%\.minecraft\saves
Mac ~/Library/Application Support/minecraft/saves
Linux ~/.minecraft/saves

In Minecraft: Singleplayer → pick the world → Edit → Open World Folder.

How to get new biomes and caves in an old Minecraft world

Drop your world folder (or a .zip of it) on the page.

Move the slider to choose how long you must have spent somewhere for it to stay.

Check the map: green stays, grey grows back new.

Download the updated copy, unzip it into your saves folder and open it in the newer Minecraft.

Walk into the grey areas — they generate fresh with the new update's terrain.

What it does

Keeps the places you spent time near, using the time Minecraft itself records in every chunk

Also keeps anything you made — signs you wrote on, chests with your things, pets, item frames

Always keeps your bed, where you're standing and the world spawn, plus a safety border

A map of what stays and what grows back before anything changes

Overworld, Nether and End, every Java world layout up to 26.x

Makes a new copy — your original world is never touched

Runs in your browser; your world is never uploaded

Questions

Why don't new biomes appear in my old world?

Minecraft only uses the new terrain for chunks it generates for the first time. Everywhere you've already loaded is saved with the terrain of the version that made it. Clearing the chunks you never really used makes Minecraft generate them again — with the new terrain.

Will I lose my builds?

No. Every chunk has a counter of how long players were nearby, and anything you spent time near stays, with a border around it. Chunks with things you made — a sign you wrote on, a chest with your stuff, a pet, an item frame — stay too, and so do your bed, your position and the spawn. You also get a new copy; the original isn't changed.

Which Minecraft version do I need?

Open the updated copy in a newer version than the one that made the world. If you open it in the same version, the cleared land grows back just as it was.

Does this work for Bedrock?

Not yet — Bedrock keeps chunks in a database this tool can't rewrite safely yet. It's coming. Java Edition worlds work now.

What does the “minutes” slider mean?

Minecraft adds to a chunk's counter every tick a player is within about 128 blocks of it. So five minutes means players were somewhere nearby for five minutes in total — not that you stood in that exact spot.

Update Old World

Where is my world?

How to get new biomes and caves in an old Minecraft world

What it does

Questions

Why don't new biomes appear in my old world?

Will I lose my builds?

Which Minecraft version do I need?

Does this work for Bedrock?

What does the “minutes” slider mean?

More free Minecraft tools

Update Old World

Where is my world?

How to get new biomes and caves in an old Minecraft world

What it does

Questions

Why don't new biomes appear in my old world?

Will I lose my builds?

Which Minecraft version do I need?

Does this work for Bedrock?

What does the “minutes” slider mean?

More free Minecraft tools