Terraria World Files: Back Up .wld and .twld

What the .wld and .twld world files are, where they live on your server, and how to back them up safely so a bad update or mod change never costs you your world.

3 min read · Updated Oct 5, 2026 · By GuavaHost Team

Your whole Terraria world lives in a couple of small files. Knowing which files matter, and getting into the habit of backing them up before anything risky, is the single best way to protect months of building.

What each file is

• WorldName.wld This is the world itself: the map, the terrain, your builds, chests and their contents, NPCs, everything. This is the file you cannot lose.
• WorldName.wld.bak A rolling backup that vanilla Terraria writes automatically. It holds the previous save, which can rescue you from a corrupted .wld, but it is only one save old, so do not rely on it alone.
• WorldName.twld On tModLoader, this companion file stores the modded parts of your world that vanilla cannot hold. A tModLoader world is really the pair .wld plus .twld, and they must be kept together.

The short version: on vanilla Terraria you care about the .wld. On tModLoader you must keep the .wld and the .twld together as a set, or the modded world data will not match.

Where to find them

1. Open your server in the control panel and go to the Files tab.
2. Look in the server's worlds folder. It is commonly a Worlds folder, and the exact path is whatever your world= line in serverconfig.txt points to.
3. You will see your .wld file there, its .wld.bak, and on tModLoader the matching .twld.

The easy way to back up: the Backups page

GuavaHost gives every server snapshot backups built in.

1. Open Backups in the server menu.
2. Click Create backup. A name is optional. This captures your whole server, world files included, in one go.
3. Restore any time with Restore next to a backup. Remember that restoring overwrites the current files, so it rolls the world back to how it was at that point.

Always take a snapshot here before a risky change: updating tModLoader, adding or removing mods, editing config, or trying anything you are unsure about.

These are quick backups, stored on the same machine as your server. For a world you can't afford to lose, Daily Off-site Backups also copy the whole server to separate cloud storage every day and keep the last 7, so a problem with the machine itself can't take your backups with it.

Keeping a copy on your own computer

It is smart to also keep a copy off the server now and then.

1. Open the Settings tab and expand Connection details. Under File access (SFTP) note the address (host), port and username, and use Set SFTP password to choose a password. SFTP is a secure way to move files between your computer and your server.
2. Connect with the free client FileZilla, or download the files straight from the Files tab. You can also Download a whole backup from the Backups page.
3. Download the .wld, and on tModLoader the matching .twld, and keep them somewhere safe. Grab both together so the pair stays complete.

Press Stop at the top of the server page before copying the world off, so you capture a clean save rather than one mid-write.

Restoring a world you saved

1. Press Stop at the top of the server page.
2. On the Files tab, open the worlds folder and use Upload files to put your .wld (and .twld for tModLoader) back.
3. Make sure serverconfig.txt has world= pointing at that file.
4. Start the server and watch the Console to confirm it loads.

Troubleshooting

• Modded world loads but modded content is missing or resets: you restored the .wld without its matching .twld. Put both back together.
• World will not load or looks corrupted: try the .wld.bak by renaming it to .wld, or restore a snapshot from the Backups page.
• Changes did not save: the server may not have written the world yet. Stop it cleanly with Stop so it saves before you copy anything.

Still stuck? Jump into our Discord at discord.gg/GuavaHost and the team will help you out.

• terraria
• tmodloader
• world
• backup
• wld

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