Sky Factory 42026-06-17 · 7 min read

Sky Factory 4 Server Setup Guide

Sky Factory 4 is one of the most downloaded Forge modpacks ever made. Setting up a dedicated server takes 10–15 minutes once you have the server pack — this guide covers every step.

Step 1: Choose your RAM

6 GB 2–8 players

Comfortable starting point for a small SF4 group. Covers early to mid-game automation well.

8 GB 8–16 players

Better for active mid-game with several automation systems running simultaneously.

10 GB 15–25 players

Late-game with heavy automation, many active machines and chunk loading pressure.

12 GB 20–40 players

Community SF4 server with high player activity and complex builds.

Steps 2–5: Install and configure

2

Download the SF4 server pack from CurseForge

Go to CurseForge, find Sky Factory 4, and download the server files (not the client modpack). Extract to your server directory.

3

Run the Forge installer

The server pack includes a Forge installer jar. Run `java -jar forge-installer.jar --installServer` to install Forge into the directory. This is the most commonly missed step.

4

Accept the EULA

Edit eula.txt and set `eula=true`. The server won't start without this. This is a Mojang requirement.

5

Set Java 8 as the runtime

SF4 runs on Minecraft 1.12.2 which requires Java 8. Make sure your start script points to the Java 8 JRE, not a newer version. The pack's included start.sh usually handles this correctly.

6

Start the server and share the IP

First boot takes 3–7 minutes. Once the console shows 'Done', players can connect via direct IP on the default port 25565. Make sure clients use the same SF4 version from CurseForge.

FAQ

Where do I download the Sky Factory 4 server pack?+
From CurseForge — search 'Sky Factory 4' and download the server files pack (not the client pack). The server pack includes the correct Forge version and all mods pre-assembled.
What Forge version does SF4 use?+
Sky Factory 4 runs on Minecraft 1.12.2 with Forge. The CurseForge server pack includes the correct Forge installer — run it first before starting the server.
How long does SF4 take to start?+
First boot takes 3–7 minutes as Forge loads all mods. Subsequent starts are faster (1–3 minutes) once the Forge registry cache is built.
Can players use different launcher clients?+
Yes — CurseForge App, Prism, MultiMC and ATLauncher all work client-side. The server doesn't care which launcher players use as long as the mod list and versions match.
Does SF4 work with Java 21?+
No — SF4 runs on Minecraft 1.12.2 which requires Java 8. Use Java 8 on the server; newer Java versions will fail to start.

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