How do you make a modded Minecraft server?
The quickest way is to pick a modpack when you create the server – the host installs the loader, the mods and the config for you. If you want your own mod list, choose a mod loader (Forge, NeoForge or Fabric) on the same Minecraft version as your mods, then add mods from the in-panel catalog or upload your own .jar files.
So you have two routes:
| Route | Best for | Effort |
|---|---|---|
| A. Ready-made modpack | Playing a well-known pack (Better MC, All the Mods, RLCraft…) | A few clicks, everything matched |
| B. Your own mods | You already have a mod list, or want to start small | Pick a loader and version, add mods one by one |
What's the difference between client mods and server mods?
Mods you install in your launcher run on your PC; mods on the server run on the server – and most mods need to be in both places. A modded server only lets you in if your game has the same loader and the same mods (in the same versions) as the server.
Mods come in three flavours:
- both sides (most content mods: new blocks, mobs, biomes, machines) – required on the server and on every player's client,
- client-only (shaders, minimaps, UI and graphics tweaks) – each player installs them locally; never put them on the server, they can crash it on startup,
- server-only (permissions, performance, backups) – only the server needs them.
The mod catalog in the Spot.gg server panel hides client-only mods, so you can't accidentally install something that stops your server from starting.
Route A: how do you start a server with a modpack?
Pick the pack from the catalog when you activate the server – the host does the rest. The catalog has over 1 200 modpacks from CurseForge, Modrinth and FTB.
- Create a Spot.gg account and confirm your email.
- Click "Activate a free server" and choose Minecraft.
- Choose a modpack – search by name or browse the modpack catalog.
- Set the RAM. Modpacks start at 6 GB (from $7.55 / month after the free trial); big packs get their recommended memory straight away.
- Wait for the install to finish and copy the server address from the panel.
Your friends just install the same modpack in their launcher (CurseForge App, Modrinth App, Prism Launcher…) and join using the server address.
Route B: how do you make a server with your own mods?
Choose the loader and Minecraft version your mods are built for, then install mods from the catalog or upload your own files. Order matters: loader first, mods second.
1. Forge vs Fabric vs NeoForge – which loader should you pick?
The one your mods are made for – a Fabric mod won't run on Forge and vice versa. Every mod page (in our catalog, on CurseForge or on Modrinth) lists the loader and the Minecraft version it supports.
- Forge – the original mod loader, with the largest library of big mods and modpacks, especially on older versions (1.12.2, 1.16.5, 1.20.1).
- NeoForge – the successor to Forge since 1.20.1; most new large mods for 1.21+ ship on NeoForge.
- Fabric – lightweight and quick to update to new Minecraft releases; lots of performance and quality-of-life mods.
If you already have a mod list, count which loader most of them support and go with that. Starting from scratch on a recent version? NeoForge or Fabric is usually the right call.
2. How do you install mods on a Minecraft server?
Open "Addons" in the server panel, search for the mod, click "Install" and restart the server. The panel only lists builds for your server's loader and highlights the one for your Minecraft version at the top.
Watch out for:
- dependencies – many mods need library mods (for example Fabric API, Architectury API or GeckoLib). Check the mod page for requirements and install them the same way,
- one Minecraft version – every mod has to match the server's game version,
- restart – new mods only load after a server restart.
3. How do you upload your own mod (.jar)?
Upload the file to the mods folder in the "Files" tab or over SFTP, then restart. Handy when a mod isn't in the catalog or you're running a custom build.
Uploading your own files is also how you add mods from outside CurseForge and Modrinth – Spot.gg doesn't limit you to an approved list.
4. How much RAM does a modded server need?
On Forge, NeoForge and Fabric the minimum is 6 GB, and large modpacks need 8–12 GB. Every mod uses some memory; with hundreds of mods and too little RAM the server takes ages to load or never finishes starting.
| Server | RAM (rough guide) |
|---|---|
| A handful of mods | 6 GB |
| 50–150 mods or a mid-sized pack | 8 GB |
| Large modpack (200+ mods), several players | 10–12 GB |
A modded server starts at $7.55 / month, and you can change the RAM at any time if you run short.
How do you play modded Minecraft with friends?
Everyone needs the same loader and mods as the server; then they join with the server address. The easiest way:
- Modpack – friends install the same pack in CurseForge App or Modrinth App and pick the same version as the server.
- Your own mods – share a list of mods (names and versions) or zip up your
modsfolder. Launchers like Prism Launcher and Modrinth App can also export a whole profile as a single file. - Joining – in Minecraft: "Multiplayer" → "Add Server" → the address from the panel.
- Security – playing with friends only? Turn on the "Whitelist" and add their usernames.
Note that Bedrock players (phones, consoles) can't join a modded Java server.
What should you do when a modded server won't start?
It's usually a missing dependency, a mod for the wrong Minecraft version or loader, or a client-only mod. The server panel lists detected problems in the "Errors" tab, and you can click "Ask the assistant" at any time – the AI assistant reads the server logs and tells you which mod is causing trouble.
Common causes and fixes:
| Symptom | Cause | Fix |
|---|---|---|
| Server stops on startup mentioning a missing mod | Missing dependency | Install the required mod (its name is in the log) |
| Version mismatch error | Mod for another Minecraft version or loader | Install the build that matches the server |
| Crash right after adding a mod | Client-only mod (graphics, shaders, UI) | Remove it from the server's mods folder |
| Very slow start, server shuts down | Not enough RAM | Give the server more RAM |
| A player can't join | Different mods or versions on their side | Compare their mod list with the server's |
To switch loader or Minecraft version on an existing server, go to "Information" → "Modify" → "Change engine" – your world stays put.
Can you run any mods on free Minecraft hosting?
Usually not fully: free hosts let you install mods and packs only from their own list, without uploading your own files. On Spot.gg you can test your mod setup free for 24 hours, and if everything works, extend the server and keep playing on the same world. See our Minecraft server hosting page for plans and prices.
FAQ
Do mods have to be installed for every player?
In most cases, yes. Mods that add blocks, items or mobs must be on the server and on every player's client, in the same versions. The exceptions are server-only mods (e.g. permissions) and client-only mods (e.g. shaders).
Forge or Fabric – which is better for a server?
Neither is better on its own – pick the one your mods are made for. Forge and NeoForge have more large mods and modpacks; Fabric is lighter and updates to new game versions faster.
Can I use mods and plugins at the same time?
Mods (Forge, NeoForge, Fabric) and plugins (Paper, Spigot) run on different server software. If you need both, check whether the plugin has a mod equivalent – most popular ones (permissions, voice chat, maps) do.
How much does a modded Minecraft server cost?
On Spot.gg a modded server starts at $7.55 per month (6 GB RAM), and the first 24 hours are free, no card required.
How do I add mods to an existing server without losing my world?
Install them from the "Addons" tab or upload them to the mods folder and restart – the world stays. Mods that add new biomes or structures will show up in newly generated parts of the world.
Can I switch to a different modpack?
Yes, under "Information" → "Modify" → "Change pack". Changing the pack reinstalls the server and removes its files, so download a copy of your world first – and keep in mind a world from one pack rarely works with another. Changing only the engine ("Change engine") keeps your world.
