Changing version
Swapping your server's engine — from Vanilla to Paper, from 1.20 to 1.21, from Forge to NeoForge — is two clicks away in the Game Panel. The catch is picking the right engine for what you want to do. This guide walks every category in the version picker, explains who each one is for, and shows the install flow end-to-end.
Before you start
Changing version reinstalls the server JAR. Your world files, plugins, mods and configs are kept by default — but a downgrade across major versions (e.g. 1.21 → 1.20) can corrupt the world, and plugins/mods built for one engine usually don't load on another. A few minutes of preparation saves an hour of recovery:
- Take a full backup. Open Backups in the panel and click Create. Wait for it to finish before you touch anything.
- Stop the server. The installer will refuse to run on a live process. Use the dashboard Stop button — don't kill it.
- Note your current build. Type
versionin the console (or read the last startup log) so you can roll back if needed. - Decide if you want a clean slate. If you're switching engine families (e.g. Forge → Paper), a wipe is usually cleaner than fighting incompatible mods. More on this below.
Minecraft worlds are forward-compatible, not backward. Loading a 1.21 world on a 1.20 server can corrupt chunks, lose entities, or wipe newer blocks. If you must downgrade, restore from a backup taken before the upgrade — don't try to "convert" the world in-place.
Opening the version picker
Sign in to the Game Panel, open your server, and click Version in the left sidebar (it's the tab with the loop-arrow icon). You'll see every supported engine grouped into five categories:
- Recommended — the engines 95% of servers should pick.
- Established — mature forks for specific use cases.
- Experimental — newer projects, mostly stable, occasional rough edges.
- Miscellaneous — niche hybrids and specialised forks.
- Limbos — featherweight servers that just hold players in a queue or fallback lobby.
Each card shows the engine's icon, name, how many Minecraft versions it supports, and how many builds are available. Cards with a ⚠ warning mark are flagged Experimental; cards with a 💀 (like Waterfall) are end-of-life and shouldn't be used for new servers.
Recommended engines
These six cover almost every use case. Pick from this row unless you have a specific reason not to.
Vanilla 822 MC versions · 822 builds — official Mojang server, no plugins/mods
Paper 64 MC versions · 5,538 builds — fastest plugin server, drop-in for Vanilla
Fabric 475 MC versions · 39,900 builds — lightweight mod loader, fast updates
Forge 58 MC versions · 4,311 builds — original mod loader, biggest mod library
NeoForge 28 MC versions · 1,508 builds — modern Forge fork, where most new mods go
Velocity 11 project versions · 475 builds — proxy for connecting many servers
Vanilla
Mojang's untouched server. Pick this if you want pure Minecraft, no plugins, no mods, no surprises. It's also the right choice if you're building snapshot/experimental worlds — Vanilla supports every MC version Mojang has ever shipped (822 at the time of writing), including weekly snapshots.
- ✅ Adventure maps, hardcore worlds, snapshot testing, parity with the Minecraft launcher.
- ❌ Anything that needs a plugin (anti-cheat, claims, economy, custom commands).
Paper
A high-performance fork of Spigot. Compatible with all Bukkit/Spigot plugins, with massive performance and stability improvements. This is the default choice for survival/SMP servers.
- ✅ Plugins (LuckPerms, EssentialsX, WorldEdit, …), 2×–4× better TPS than Vanilla, regular security patches.
- ❌ Mods. If you want both plugins and mods, see Arclight or Mohist under Miscellaneous.
Fabric
A small, fast mod loader that updates to new MC versions within hours of release. Most modern performance mods (Lithium, Sodium's server companions, FerriteCore) are Fabric-first.
- ✅ Light modpacks, snapshot modding, performance-focused builds, latest MC version on day one.
- ❌ The huge legacy mod library that Forge has. Most big modpacks ship as Forge or NeoForge.
Forge
The original Minecraft mod loader and still the biggest mod ecosystem — anything with "Tech" or "Magic" in the name (IndustrialCraft, Thaumcraft, Create…) is Forge first. Updates slower than Fabric.
- ✅ Large established modpacks, kitchen-sink builds, anything from CurseForge tagged Forge.
- ❌ Plugins. Newer mods increasingly skip Forge for NeoForge.
NeoForge
A community fork of Forge from late 2023, now where most new mod development happens. API-compatible with Forge in most cases, but with cleaner governance and faster releases.
- ✅ New modpacks (Create: Astral, ATM10, Enigmatica 10, …), anything tagged NeoForge on Modrinth/CurseForge.
- ❌ Older mods that only ship for Forge — check compatibility before switching.
Velocity
Not a Minecraft server — a proxy. Velocity sits in front of multiple backend servers (lobby, survival, minigames…) and routes players between them. Modern, fast, the default proxy for new networks.
- ✅ Multi-server networks, BungeeCord replacement, queues, cross-server chat.
- ❌ Running a single server — Velocity has no world, no game logic. You need Paper/Vanilla/etc. behind it.
For a friends-and-family SMP, a public survival server, or anything where you might want to add a plugin later — Paper is the right answer. It runs Vanilla content unmodified and gives you the option to install plugins whenever you want.
Established forks
Battle-tested alternatives to the recommended set. Pick one of these when you have a specific reason — extra performance, regionised threading, a different proxy preference.
Purpur
A Paper fork with hundreds of additional config knobs — gameplay tweaks, mob behaviour, ride mechanics, custom enchant limits. Same plugin compatibility as Paper. Good if you want to deeply customise vanilla mechanics without writing a plugin.
Pufferfish
A Paper fork focused on raw performance. Slightly more aggressive optimisations, async chunk loading, AI improvements. Use when TPS matters more than feature breadth.
Folia
PaperMC's experimental regionised multi-threaded server. Splits the world into independent regions, each ticking on its own thread — meaning a single server can host hundreds of distant players without TPS dropping. Significant caveat: many plugins are not yet Folia-compatible and need explicit support.
Sponge
An independent server platform with its own plugin API (SpongeAPI). Not compatible with Bukkit/Spigot/Paper plugins. Pick this only if you want SpongeAPI specifically — most users want Paper.
Spigot
The original Bukkit fork that Paper itself is forked from. Slower and with fewer optimisations than Paper. There is essentially no reason to pick Spigot over Paper today — plugin compatibility is identical.
BungeeCord
The classic Minecraft proxy. Still works, but Velocity is faster, safer and better-maintained. Use BungeeCord only if you have a plugin that hasn't been ported to Velocity.
Waterfall 💀
End of life. Waterfall (PaperMC's BungeeCord fork) was discontinued in 2023. The team's recommendation is to migrate to Velocity. Don't start a new network on Waterfall.
Experimental
Newer projects that are usable but may have rough edges or fast-moving APIs.
Quilt ⚠
A community fork of Fabric with a more permissive governance model. Compatible with most Fabric mods. Pick Quilt if you specifically need a mod that's Quilt-only — otherwise Fabric is the safer choice.
Canvas ⚠
A new fork in the Paper family focused on next-generation performance. Promising but young — expect occasional plugin incompatibility. Worth testing on a staging server before production.
Miscellaneous
Hybrid loaders that run plugins and mods, plus a few niche performance forks. These shine in very specific situations.
Velocity-CTD
A community fork of Velocity with extra features (extended queueing, custom Tab UI, broader plugin compatibility). Drop-in replacement for Velocity for most setups.
Arclight
A Forge + Bukkit hybrid. Runs Forge mods alongside Bukkit/Spigot/Paper plugins. Lets you build modpack-style content with the rich plugin ecosystem on top. Tradeoff: heavier RAM use and occasional crash edge-cases when mod and plugin features collide.
Mohist
The other big Forge + Bukkit hybrid, similar to Arclight. Mohist supports more legacy Forge versions; Arclight tends to be faster on modern ones. Pick whichever has better builds for your target MC version.
Magma
Yet another Forge + Bukkit hybrid, focused on 1.12/1.16 era modpacks. Useful if you're hosting an old Forge pack and want to add admin plugins.
DivineMC
A Paper-family fork with aggressive multi-threading and async optimisations. Similar idea to Folia but with broader plugin compatibility. Still maturing.
Leaf & Leaves
Two separate (and confusingly similarly-named) Paper forks focused on small-server performance and quality-of-life. Both compatible with Bukkit plugins. Pick based on which has builds for your MC version.
ASPaper
"Async Paper" — a Paper fork that moves additional subsystems off the main thread. Niche; useful for very high player counts on a single instance.
Limbos
NanoLimbo
A lightweight server that does nothing except hold players in a void world. Used behind a proxy as a "fallback" when your main server is restarting, or as a "queue" room. Uses tiny amounts of RAM (under 50 MB). Not a game server — only useful as part of a Velocity/BungeeCord setup.
Picking the Minecraft version
Click any engine card and the panel switches to a list of supported Minecraft versions, newest first. Using Paper as an example:
[ ← Go Back ] [ 📦 Show Snapshot Versions ]
1.21.12 RELEASE 61 builds
1.21.11 RELEASE 92 builds
1.21.10 RELEASE 51 builds
1.21.9 RELEASE 20 builds
1.21.8 RELEASE 55 builds
1.21.7 RELEASE 28 builds
1.21.6 RELEASE 46 builds
1.21.5 RELEASE 111 builds
1.21.4 RELEASE 224 builds
1.21.3 RELEASE 82 builds
1.21.1 RELEASE 128 builds
1.21 RELEASE 129 builds
...
- Go Back — returns to the engine grid.
- Show Snapshot Versions — toggles weekly snapshots and pre-releases into the list. Don't use snapshots in production — they ship breaking changes and known bugs.
- RELEASE tag — stable, recommended.
- Build count — how many builds of that MC version exist. A version with many builds (e.g. 1.21.4 — 224 builds) has been around longer and is more battle-tested.
The very newest version usually has few builds, fewer compatible plugins, and the most rough edges. Drop back one minor version (e.g. 1.21.11 instead of 1.21.12) and you'll have a wider plugin selection and a more stable server.
The Install modal
Click a Minecraft version and an Install modal slides in. Using Paper 26.1.2 as the example:
Install Paper 26.1.2 [ × ]
[ Build #64 v ]
┌─────────────────────────────────────────────────────────┐
│ ⚪ WIPE SERVER FILES │
│ This will delete all files on your server before │
│ installing the new version. This cannot be undone. │
└─────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────┐
│ ⚪ ACCEPT EULA │
│ By enabling this option you confirm that you have │
│ read and accept the Minecraft EULA. │
│ (https://minecraft.net/eula) │
└─────────────────────────────────────────────────────────┘
[ Cancel ] [ Install ]
Build dropdown
Defaults to the latest build for that MC version. The build number (#64) is the engine's internal build counter — higher = newer. For Paper specifically, builds tagged main are stable; experimental ones are not. Stick with the default unless you have a specific reason.
Wipe Server Files
Off by default — and that's almost always what you want. Leaving this off keeps your world, plugins, mods and configs in place. The installer only swaps the server JAR.
Flip it on only when:
- You're switching engine families (e.g. Forge → Paper) and you know the old mods won't load on the new engine.
- You want a fresh start — new world, new configs, clean slate.
- The current install is broken beyond repair and you've already pulled what you want via SFTP or a backup.
The modal says it for a reason. Wiping deletes everything: world folders, plugins, mods, configs, logs. There is no undo. Take a backup first.
Accept EULA
Mandatory for any non-Vanilla Minecraft server. The Mojang EULA forbids charging for in-game advantages — read it once at minecraft.net/eula. If this toggle is off, the server will write eula=false to eula.txt on first start and refuse to boot.
Hitting Install
Press Install. The panel will:
- Download the new server JAR (a few hundred MB for modded engines, ~50 MB for Paper/Vanilla).
- If Wipe was on — delete the existing server files.
- Replace the server JAR and update the startup command.
- Set
eula=trueineula.txtif you accepted. - Display a toast confirming success.
Installation usually takes 30 seconds to 5 minutes depending on engine size and your storage tier.
After installing
- Go to the dashboard.
- Click Start.
- Watch the console. First boot is slower — the server is generating data files, copying registries, and (for Forge/NeoForge) running its installer.
[INFO] Starting minecraft server version 1.21.11
[INFO] This server is running Paper version 1.21.11-64-main
[INFO] Loading libraries, please wait...
[INFO] Preparing level "world"
[INFO] Time elapsed: 4521 ms
[INFO] Done (8.412s)! For help, type "help"
Confirm the line This server is running <Engine> version <MC>-<build> shows the engine and MC version you picked. If it doesn't — stop the server, check the install completed cleanly, and try again.
Post-switch checklist
- Plugins/mods. If you kept the existing
/pluginsor/modsfolder, scan the startup log for failed loads. Plugins built for an older API may need updating — open Adding plugins for the install flow. - server.properties. Some engines write fresh defaults on a wipe. Compare with your backup if specific settings (gamemode, MOTD, ports) reverted.
- Performance. Switching from Vanilla to Paper/Purpur often doubles TPS — set
view-distanceandsimulation-distanceto comfortable values now. - Client version. Tell your players which MC version to connect with. Mismatch causes the "Outdated server" / "Outdated client" disconnect.
Rolling back
If the new version broke something:
- Stop the server.
- Open Backups, find the snapshot you took before changing version, and click Restore.
- Go back to Version and reinstall the previous engine/MC version.
- Start the server.
If you don't have a backup, you can still reinstall the previous engine — your world data is usually still on disk — but any block changes made since the switch will reflect the newer version's chunk format and may not load cleanly on a downgrade.
Common issues
- Server won't start after the switch. Check the console for
UnsupportedClassVersionError— the new engine probably needs a newer Java than the panel is providing. Open Startup and pick a higher Java image (Java 21 for MC 1.20.5+). - All plugins fail with
incompatible API. You switched engine families (e.g. Paper → Sponge). Reinstall plugins from the Sponge ecosystem, or switch back to Paper. - World won't load:
InconsistentDimensionExceptionormissing chunk. You downgraded MC versions. Restore from a backup taken before the upgrade. - EULA error on start. You unticked Accept EULA in the modal. Either flip the toggle and reinstall, or edit
eula.txtdirectly via Files toeula=true. - "Snapshot not stable" warnings. You picked a snapshot version. Switch back to a RELEASE build for production use.
- Engine card missing. Some engines only support a subset of MC versions — e.g. Folia only ships for recent releases. If you don't see the version you want, the engine doesn't support it yet.
Still stuck? Open a ticket with your console log and the engine/version you tried to install — we'll dig in.