--- title: "How to install a Minecraft modpack on your server" description: "Modrinth or CurseForge, the loader you don’t have to pick, the real JVM heap per tier, and why the first boot takes twenty minutes." url: https://tickserv.com/en/guides/install-minecraft-modpack site: "TickServ (https://tickserv.com)" lang: en published: 2026-07-16 updated: 2026-08-22 games: [minecraft] --- # How to install a Minecraft modpack on your server A modpack changes everything: new mods, dimensions, mechanics, sometimes five hundred mods at once. Running a modded server isn't hard — provided you understand three things tutorials tend to skip: where the loader comes from, how much memory the server actually gets, and why the first boot takes twenty minutes. ## Modrinth or CurseForge: what actually differs Both platforms cover most modpacks, but they don't distribute them the same way. - **[Modrinth](https://modrinth.com/modpacks)** is open: packs download without an API key, and third-party redistribution is allowed. Paste the URL (`modrinth.com/modpack/…`) or even just the pack's **slug** — both are accepted. - **[CurseForge](https://www.curseforge.com/minecraft/modpacks)** requires a host-side API key to install automatically. Here you must paste the **full URL** (`curseforge.com/minecraft/modpacks/…`): a bare slug would be ambiguous with Modrinth, so it's rejected. That's why a Modrinth pack always installs while a CurseForge pack depends on the host. If you're self-hosting, the same rule applies: Modrinth you fetch directly, CurseForge needs a key. ## You don't have to pick the loader or the version This is what wastes the most time installing by hand: Fabric, Forge and NeoForge aren't interchangeable, and a pack only runs on its own, at one specific Minecraft version. The good news: **the pack carries that information.** The loader and Minecraft version are set by the modpack, not by you. You paste a link, the rest is derived. Same for Java — each Minecraft version demands a minimum (Java 21 since Minecraft 1.20.5, [Minecraft Wiki](https://minecraft.wiki/w/Server/Requirements)) and it's chosen for you. What you do have to check is the **pack version** your friends install client-side. A content mod has to be present on both sides, at the same version: that's the number-one cause of "connection refused" and "mod mismatch". ## The ready-to-run modpacks Ten packs are offered directly, with no link to hunt down: | Pack | Loader | Minecraft | Genre | | --------------------- | -------- | --------- | ------------ | | All the Mods 10 | NeoForge | 1.21.1 | kitchen-sink | | COBBLEVERSE | Fabric | 1.21.1 | Pokémon | | Cobblemon Official | Fabric | 1.21.1 | Pokémon | | Vault Hunters 3rd Ed. | Forge | 1.18.2 | RPG | | Prominence II | Fabric | 1.20.1 | RPG | | Better MC (BMC2) | Fabric | 1.20.1 | adventure | | SkyFactory 4 | Forge | 1.12.2 | skyblock | | RLCraft | Forge | 1.12.2 | hardcore | | Create: Live 5 | Forge | 1.20.1 | tech | | Adrenaline | Fabric | 1.20.1 | performance | ![The modpack picker when creating a Minecraft server: ready-to-run modpacks (All the Mods, RLCraft, Cobblemon…) and a field to paste a Modrinth or CurseForge link](https://tickserv.com/shots/modpack-light.webp '464x353') ## RAM: what the server actually gets Here's the most useful thing in this guide, and the one no modpack page explains. When a pack author writes "allocate 8 GB", they mean the **JVM heap** (`-Xmx`) — not the machine's memory. And the two are never equal: the operating system, Docker and Java's own off-heap memory (metaspace, buffers) live **beside** the heap. Give all the RAM to the JVM and the kernel will kill your server mid-game. So the heap is worked out for you, and it equals **the smaller of "RAM − 2 GB" and "75% of RAM"**: | Tier you pick | Actual JVM heap | What it covers | | ------------- | --------------- | ------------------------------------- | | 4 GB | 2 GB | vanilla, or a very light pack | | 8 GB | **6 GB** | Cobblemon, RLCraft, Create: Live 5 | | 16 GB | **12 GB** | All the Mods, COBBLEVERSE, SkyFactory | | 32 GB | 24 GB | big pack plus a large group | Always translate in that direction: a pack asking for **8 GB of heap** does not fit the 8 GB tier, which only yields 6 — it needs the **16 GB** tier. That's why the creation screen warns you when the tier you picked doesn't cover the pack: it compares heaps, not machine sizes. And if exploring stutters while the heap is comfortable, memory is no longer the problem — the CPU is. The **dedicated CPU** level exists for that. ## The first boot takes fifteen to twenty-five minutes It isn't "crashing". On its first boot a modded server downloads the pack, resolves mod dependencies, writes the configuration, then generates the world — and generating a modded world is far heavier than a vanilla one, because every mod adds its own structures and biomes. A vanilla server is ready in 1 to 2 minutes. A big pack takes **15 to 25 minutes**. Later boots are quick, the world already being there. This is the classic phantom failure: people assume it failed, kill it, start over, and never finish that first boot. Let it run to the end. ## What's kept, and what isn't The data directory is archived **before every shutdown** and restored on the next session, with a `save-all flush` immediately before archiving. An automatic backup runs **every 30 minutes** while you play, of which the **last 5** are kept. What is deliberately _not_ archived: the server's libraries and binaries, which the image re-downloads each session. Your archive holds only what's yours — world, configuration, mods — and stays small as a result. ## Changing pack, or going back A modded world is inseparable from its mods: loaded without them, it loses its blocks, permanently. So don't switch packs on an existing world — create a second server. And if you're importing a modded world from elsewhere, paste the same pack at the same version **before** the import: see the [world migration guide](https://tickserv.com/en/guides/move-minecraft-world). > Ready? [Create your Minecraft server](https://tickserv.com/en/games/minecraft) and paste your modpack. Your first session is free.