Creating a Modded Minecraft Server in 2026: The Guide

Introduction

A modded Minecraft server turns the base game into something else entirely: an RPG with dungeons and classes, a giant factory to automate, a world of magic and creatures, or all three at once. The trade-off is that it takes more preparation than a classic Vanilla or Paper server: you need to pick a modloader, size your RAM correctly, install mods in the right place on both the server and the client side, and know how to react when something breaks (because it will, at least once). This guide walks you through it all, with Forge or Fabric, on a SERV-Minecraft server.

Forge or Fabric: which modloader should you choose?

A modloader is the software that attaches to the Minecraft server to let it load mods (extensions that add blocks, items, mechanics, dimensions, and so on). Two of them dominate the modpack ecosystem by far: Forge and Fabric. The choice isn't cosmetic: a mod compiled for Forge won't run on Fabric, and vice versa. It's the very first decision to make, even before ordering your server.

Forge, the essential veteran

Forge has been around since the early days of Minecraft modding. It's the most widely used modloader, with by far the largest catalog of mods available on CurseForge. Nearly all of the big technical or RPG-oriented modpacks (All the Mods, SkyFactory, RLCraft, Pixelmon, and so on) run on Forge. The downside: Forge mods can be heavier to load and slower to update on the very latest Minecraft versions.

Fabric, the light and modern option

Fabric is more recent, lighter, and generally updated faster after a new Minecraft version comes out. Its mod catalog is smaller than Forge's, but it covers quality-of-life mods, optimization, and "enhanced vanilla" style modpacks very well. Fabric also needs the companion mod Fabric API for most other mods to work: always remember to install it first.

Forge vs Fabric at a glance

In practice, the question to ask yourself isn't "which one is better" but "which modpack or mods do I want to run". If you're starting from an existing modpack (see our modpack selection), the modloader is already dictated by the pack: you just have to follow it.

How much RAM for a modded server?

This is the question that comes up the most, and the honest answer is "it depends on the number and weight of the mods", but here are cautious benchmarks so you don't come up short:

• Small pack (20 to 60 mods, quality-of-life, vanilla+): 6 to 8 GB is enough to play comfortably with friends.
• Medium modpack (100 to 200 mods, Create-based or adventure type): plan for 10 to 16 GB to stay comfortable while playing together.
• Big technical or RPG modpack (300+ mods, All the Mods, SkyFactory, Pixelmon, and so on): 16 to 24 GB, or more if you're hosting a large community.

These figures are deliberately cautious: it's better to have margin than lag. On SERV-Minecraft, the Modded (24 GB, €15.99/month) plan comfortably covers the vast majority of medium to large modpacks, with room to add mods along the way. If you're aiming for a very large community pack, the Modpack plan (32 GB) also exists: ask for advice via the panel if you're torn between the two.

Step 1: order your modded server

1. Go to the modded Minecraft server page or directly to the plans.
2. Choose the Modded plan (24 GB) or Modpack plan (32 GB) depending on the size of the pack you're targeting.
3. Confirm your order on https://panel.serv-minecraft.fr/commander: no commitment, near-instant activation.
4. Once the server is active, head to the panel for the modloader installation step.

Step 2: install Forge or Fabric from the panel

On the SERV-Minecraft panel, every server has a Version tab with two dropdown menus: "Edition" (Vanilla, Paper, Forge, Fabric, Bedrock depending on available versions) and "Version" (the Minecraft version). The process is the same for a new server or to switch modloaders later:

1. Open your server in the panel, Version tab.
2. Select Forge or Fabric in the "Edition" menu.
3. Choose the Minecraft version matching the modpack or mods you're targeting.
4. If the server isn't new, only check "Format the server" if you're sure you want to start from scratch: this box deletes all existing files.
5. Click "Install version" and let the installation run (it starts in the background, and takes a few minutes depending on the modloader and version).

Once the installation is done, start the server from the Console tab ("Start" button) and watch the first log lines: that's where you'll immediately see whether the modloader installed correctly.

Step 3: add mods on the server side

Mods go into the /mods folder at the server's root. Two ways to send them with the SERV-Minecraft panel:

• From the panel's file manager (Files tab): open the mods folder, use "Upload files" and select the .jar files you've already downloaded.
• From an SFTP client: the panel exposes SFTP access (credentials visible in the Advanced tab), handy for sending a lot of mods at once or syncing a local folder.

Download your mods from trusted sites, checking carefully the Minecraft version and modloader shown on the mod's page:

• CurseForge (curseforge.com): the largest catalog, Forge and Fabric.
• Modrinth (modrinth.com): more recent, lightweight interface, very well stocked with Fabric mods.

For Fabric, never forget to install Fabric API first: it's a near-universal dependency for other mods. After adding or removing any mod, restart the server (a simple reload isn't enough to load or unload a mod).

your-server/
├── mods/
│   ├── fabric-api-x.x.x.jar
│   ├── mod-a-x.x.x.jar
│   └── mod-b-x.x.x.jar
├── config/
├── world/
└── server.properties

Step 4: install the same mods on the client side

This is the step many players forget: to join a modded server, each player needs the same modloader installed, the same Minecraft version, and above all the same mods (at least the ones marked as required client-side) as the server. Even a minor mismatch usually blocks the connection or causes crashes.

1. Install the official Minecraft launcher, then Forge or Fabric in the same version as the server (each modloader's official site provides a dedicated installer).
2. Copy the same mods folder as the server's into the client's .minecraft/mods folder (remove mods that are purely "server-side" if they're marked as such on their page).
3. A simpler alternative for a full modpack: use a third-party launcher like the CurseForge app or the Modrinth App, which automatically installs the right modloader and all the pack's mods in one click.
4. Launch Minecraft with the right profile, then connect to your server's IP address (visible in the panel's Console tab).

Step 5: launch and join the server

From the panel's Console tab, start the server with the "Start" button and follow the loading live. The CPU, RAM and disk graphs shown next to the console give you an instant read on the modpack's real load: if RAM climbs close to 100% right after an empty startup, that's the signal to move up to the next plan. Once the loading-complete message appears, copy the server's IP address and share it with your players (who need to have followed step 4).

Fixing common crashes

The server crashes immediately on startup

Open the crash-reports/crash-<date>-server.txt file (or logs/latest.log) from the panel's file manager. The cause is almost always spelled out clearly in the first lines: a mod incompatible with the Minecraft version, a missing dependency, or two mods changing the same thing (a mixin conflict).

"Out of memory" / OutOfMemoryError

The modpack needs more RAM than what's allocated. Check the actual usage in the panel's Resources tab while the server is running, and move up a RAM tier if it stays maxed out, rather than removing mods.

"Missing dependency" or a required mod is missing

The message usually gives the exact name of the missing mod (for example Fabric API, or a library like Cloth Config). Download it in the matching version and restart.

Conflict between two mods (mixin / crash when loading a block or entity)

Remove the most recently added mods one by one until you find the culprit, restarting after each removal. It's tedious but reliable. Also check that all your mods target the exact same Minecraft version: a mismatch of even a single sub-version (1.20.1 vs 1.20.4, for example) is enough to break everything.

The server runs but lags heavily with lots of mods

This is a whole topic on its own: Paper/Purpur settings, JVM flags, view distance, and more, all covered in our guide 15 tips to optimize a Minecraft server.

FAQ

Can I mix Forge mods and Fabric mods?

No. Forge and Fabric are two completely incompatible modloaders: a mod compiled for one will never work on the other, even if it exists for both separately (in that case, they're two different .jar files to download).

How many mods can I install on my server?

There's no technical limit imposed by the panel, but the real limit is the available RAM and CPU power. A modpack built and tested by its community (like the ones listed in our modpack selection) remains the safest choice, rather than stacking dozens of mods picked at random.

Do I need to reinstall the server to switch modloaders?

Not necessarily a full reinstall: you can change edition from the panel's Version tab. However, switching from Forge to Fabric (or the other way around) makes your old mods unusable, so you'll need a new mods folder suited to the new loader either way.

Why does my modded server use more RAM than a regular Paper server?

Each mod adds its own code, its own entities, and sometimes its own generated dimensions or structures, on top of Minecraft's base load. The more mods are active, the more RAM is needed, which is why the modded plans (Modded, Modpack) offer more RAM than the Plugins plan.

Which plan should I choose to start a modded server?

For the vast majority of medium to large modpacks, the Modded plan (24 GB, €15.99/month) is the recommended starting point: enough headroom for a full pack without paying for unused RAM.