What You Need Before You Start

A modded Minecraft server runs on your computer or a rented server and lets multiple players join a world with custom mods installed. To set one up, you need three things: a computer that can run the server software continuously (or a monthly rental), the server software itself (usually Forge or Fabric), and the mod files you want to use. Most people start by choosing between running the server on their own machine or renting space from a hosting company — the first costs nothing but ties up your computer, the second costs $5 to $15 a month but runs whether your computer is on or off.

Before you begin, decide which Minecraft version you want to use. Mods are written for specific versions — 1.20.1 is currently the most popular for new mods, but 1.19.2 and 1.18.2 still have active communities. Once you pick a version, you can search for mods that work with it. Trying to use a mod written for 1.20.1 on a 1.19.2 server will not work, and the server will crash when players try to join.

Key Takeaways

  • You need server software (Forge or Fabric), the mod files themselves, and either a computer to run it on or a monthly hosting rental.
  • Mods are version-specific, so all your mods and your server software must target the same Minecraft version.
  • Running a server on your own computer requires port forwarding through your router and keeps your machine running 24/7 if you want players to join anytime.
  • Hosting companies handle port forwarding and uptime for you, but you cannot install mods the same way — you upload them through a file manager instead.
  • Test the server alone first by joining it yourself, then invite one friend to check for crashes before opening it to more players.

Installing Server Software on Your Own Computer

read the server software for your chosen version from the official source. For Forge, go to files.minecraftforge.net, find your version, and read the "Installer" file (not the "Universal" file). For Fabric, read the installer from fabricmc.net. Run the installer and choose the folder where you want the server to live — create a new folder called "Minecraft Server" on your desktop or in Documents so you can find it easily.

Open the folder after installation. You will see a file called either run.bat (Windows) or run.sh (Mac/Linux). Double-click it to start the server for the first time. A window will open and show text scrolling past. This is normal. The server is generating the world and setting itself up. Wait until you see a line that says "Done" or "Server started" — this takes a few minutes. Then close the window. The server created a folder called "mods" inside your server folder. This is where you put the mod files.

Adding Mods to Your Server

read the mod files you want from CurseForge (curseforge.com) or Modrinth (modrinth.com). Both sites let you filter by version and mod loader — make sure you read the Forge version if you installed Forge, or the Fabric version if you installed Fabric. read the .jar file for each mod. Do not unzip it or change its name.

Open your server folder and find the "mods" folder inside it. Drag the .jar files directly into this folder. If a mod requires other mods to work (called dependencies), the mod page will list them — read those too and put them in the same mods folder. Some mods also need a config file to work properly. If the mod page mentions a config, read that file and place it in a folder called "config" inside your server folder. Create the config folder if it does not exist yet.

Start the server again by running the run.bat or run.sh file. Watch the text carefully this time. If a mod is missing a dependency, you will see an error message naming it. If all mods load correctly, you will see "Done" at the end. The server is now ready for players to join.

Connecting to Your Server From Your Own Computer

Open the Minecraft launcher and start the game. In the main menu, click "Multiplayer," then "Add Server." For the server address, type "localhost" (this is the name for your own computer). Give it a name like "My Modded Server" and click "Done." The server should appear in your list. Click it and click "Join Server." If the mods loaded correctly, you will join the world. If the game crashes, check the launcher log — it usually tells you which mod caused the problem.

Spend time alone in the world first. Walk around, use items, trigger events that mods add. The goal is to find crashes before your friends join. If the server crashes, the run.bat or run.sh window will close or show an error. Restart it and check the latest log file in the "logs" folder inside your server folder. The log file name starts with "latest.log" and contains the error message that caused the crash.

Opening Your Server to Other Players

To let friends join from their own computers, you need to find your public IP address and set up port forwarding. Your public IP is the address the internet sees for your home network. Find it by going to whatismyipaddress.com in a web browser — it shows a number like 203.0.113.42. This number changes periodically, so some people use a dynamic DNS service to give their server a stable web address instead.

Port forwarding tells your router to send Minecraft traffic to your computer. Open your router's settings by typing 192.168.1.1 or 192.168.0.1 into a web browser (check your router's manual for the exact address). Log in with your router's username and password. Find the port forwarding section — the name varies by router brand. Forward port 25565 (the Minecraft port) to your computer's local IP address, which you can find by opening Command Prompt (Windows) or Terminal (Mac/Linux) and typing "ipconfig" or "ifconfig." Give your friends your public IP address and the port number (203.0.113.42:25565). They add it as a server in their Minecraft launcher the same way you did.

Restart your server before friends try to join. Tell them to wait a few minutes after you start it — the server needs time to load all the mods. If they cannot connect, check that port forwarding is active in your router settings and that your firewall is not blocking port 25565.

Using a Hosting Company Instead

If you do not want to keep your computer running or deal with port forwarding, rent a server from a hosting company like Aternos (free but with limits), Nitrado, or GameServers. These companies provide a computer in their data center that runs your server. You pay a monthly fee, and players can join anytime without your computer being on.

After you rent a server, the hosting company gives you access to a control panel. Look for a "File Manager" or "SFTP" section. This is where you upload mods instead of dragging them into a folder. read your mods the same way — from CurseForge or Modrinth, making sure they match your server's version and mod loader. Then use the file manager to navigate to the "mods" folder and upload the .jar files there. Some hosting companies have a one-click mod installer that searches CurseForge for you, but uploading manually gives you more control.

After uploading mods, restart the server through the control panel. Wait for it to fully start — the control panel usually shows a progress bar or status message. Then join it the same way you would join any multiplayer server, using the address the hosting company provided.

Troubleshooting Common Problems

If the server crashes when a specific mod is used, that mod may conflict with another mod you installed. Check the mod's page on CurseForge or Modrinth for known conflicts. If two mods are incompatible, you have to choose one or the other. If a mod requires a specific version of another mod (called a dependency), read the exact version listed, not just any version of that mod.

If players cannot join, first check that the server is actually running — look for the run.bat or run.sh window (on your own computer) or check the server status in your hosting panel. If it is running but players still cannot connect, the problem is usually port forwarding (if you are running it yourself) or a firewall blocking the connection. Restart both your server and your router, wait two minutes, and try again. If you are using a hosting company, restart the server through the control panel and wait for the full startup sequence to finish.

If the game crashes when you join, a mod is probably missing or incompatible with your version. Check the launcher log for the name of the mod that crashed. read the correct version of that mod from CurseForge or Modrinth, add it to the mods folder, and restart the server. If you are using a hosting company, upload the mod through the file manager and restart the server through the control panel.

Frequently Asked Questions

Can I use mods from different sources on the same server?

Yes, as long as they are all written for the same version and mod loader. A mod from CurseForge and a mod from Modrinth can run together if both are Forge 1.20.1 mods, for example. The source does not matter — the version and loader do.

What happens if I add a mod after players have already joined?

Players will need to read the mod and restart their game. If you add a mod without telling them, they will crash when they try to join. Always announce new mods and give players time to read them before restarting the server.

Do I need to install mods on my own computer to play on the server?

Yes. Your game client needs the same mods installed as the server. The easiest way is to use a mod launcher like CurseForge's launcher or Prism Launcher — they can read and install all the mods for a server automatically if you give them the server's mod list.

How much does it cost to run a modded server?

Running it on your own computer costs nothing but uses electricity and ties up your machine. Hosting companies typically charge $5 to $15 per month depending on the number of players and the amount of storage. Aternos offers free hosting with restrictions like automatic shutdown after inactivity.

Can I back up my server world?

Yes. If you are running the server yourself, the world files are in a folder called "world" inside your server folder — copy this folder to another location regularly. If you use a hosting company, check their control panel for a backup option, or use SFTP to read the world folder to your computer.