Celerium

Celerium

Modpack made for stability and performance that is made for building things ontop

by Psystock
271 Downloads
0 Followers
fabricMC 1.21.11lightweightoptimization

About this Modpack

Meet Celerium!

A modpack that focuses on stability and compatibility while also being very expandable.

Goal

The goal of this modpack used to be just something that is safe for beginners but also contributes to a smooth experience, but it can be more than that, it can be a base layer for more modpacks with different goals.

How is this modpack good?

Celerium contains carefully picked mods and configurations to ensure you can enjoy a smoother Minecraft experience in your computer regardless of its specifications! Every mod that is in this pack are almost guaranteed to have little to no problems in Minecraft! As I said, this modpack contains configurations that come as defaults to you and thanks to YOSBR, these changes persist through versions, which means it just works out of the box! (You can always alter the settings in case you're unsatisfied).

Some important stuff

This modpack doesn't control how often the mods that it includes update, so I'll only update a certain mod in the pack if that update comes to my attention.
I will only update the modpack to newer versions once all the mods that it includes are updated to said version.
Although the modpack supports 1.21.4-1.21.8 + 1.21.10-1.21.11, main development and testing is done on 1.21.10, the version that the modpack originally released at.
For guides and support about the modpack, refer to the Documentation.

Can I add my own mods?

Of course you can! After all, this IS Minecraft: Java Edition, as long as the mod is compatible with the version of the game you got for the modpack and is made for Fabric, you can add it without any problems. But I advise you to be careful, some mods might not work well with others if they touch the same system, always research about what you are adding before integrating it into the pack.

Is it safe?

Of course it is! It's even open-source, you can find the link to the source and the documentation on the right, pretty useful stuff, right?

Ways of contact:

Discord: @psystock
E-mail: [email protected]

Mods included:

Alternate Current by Space Walker
BetterF3 by TreyRuffy
Better Mount HUD by Lortseam (available on 1.1.0+)
Block Entity Render Distance by LoLip_p
Cloth Config API by shedaniel
Clumps by jareddlll08
Debugify by isxander
Distant Horizons (only available in 1.0, though.) by jeseibel
Dynamic FPS by LostLuma
Entity Culling by tr7zw
Fabric API and Fabric Language Kotlin by modmuss50
FastQuit by contaria
FerriteCore by malte0811
FPS - Display by Grayray75
ImmediatelyFast by RaphiMC
Krypton by astei
Lithium by jellysquid3
Mod Menu by Prospector
Moonrise by jpenilla
MoreCulling by FX
Not Enough Crashes by natanfudge (ADDED IN 1.4.0 BUT QUICKLY REMOVED IN 1.4.1 DUE TO INCOMPATIBILITES)
Sodium by CaffeineMC (available in versions 1.2.1+)
Text Placeholder API by Patbox
Shulker Box Tooltip by MisterPeModder
YetAnotherConfigLib (YACL) by isxander, the same creator of Debugify!
Your Options Shall Be Respected (YOSBR) by shedaniel (available on 1.3.0+)
If you want to know exactly what each mod does, check the documentation

Available Versions

Celerium 1.4.2 for 1.21.11release
MC 1.21.11fabric13 downloads
April 12, 2026
Celerium 1.4.2 for 1.21.10release
MC 1.21.10fabric8 downloads
April 12, 2026
Celerium 1.4.2 for 1.21.8release
MC 1.21.8fabric8 downloads
April 12, 2026
Celerium 1.4.2 for 1.21.7release
MC 1.21.7fabric6 downloads
April 12, 2026
Celerium 1.4.2 for 1.21.6release
MC 1.21.6fabric6 downloads
April 12, 2026

How to Set Up a Celerium Server

1

Order Server

Choose at least 4 GB RAM (6 GB recommended for Celerium). Based on player count: per 8 players.

2

Install Modpack in Dashboard

Open the modpack browser in the dashboard, search for "Celerium" and click "Install". The fabric loader and Minecraft 1.21.11 are configured automatically.

3

Start Server & Play

Start the server – all mods are loaded automatically. Share the server IP with friends and play together!

Frequently Asked Questions

Celerium server crashes or won't start – what to do?

Most common causes: insufficient RAM or wrong fabric loader. Check latest.log for "OutOfMemoryError" → increase RAM to at least 6 GB. For "Mixin" or "ClassNotFoundException" errors: modpack version and loader don't match. With Mado Hosting, loader and Minecraft version are auto-configured on modpack install – preventing most startup issues.

How much RAM does a Celerium server really need?

Minimum 4 GB, recommended 6 GB for stable performance. per 8 players. Important: Minecraft modpacks need more RAM than vanilla – plan extra per additional player. With Mado Hosting, you can scale RAM up live at any time without data loss (from €8/month).

Can I add custom mods to Celerium without conflicts?

Yes, but check compatibility: only use mods for the same loader (fabric) and same Minecraft version (1.21.11). Common issues: ID conflicts with recipe mods and incompatible coremod versions. The Mado dashboard mod browser only shows compatible mods and warns about known conflicts.

Celerium server lagging – performance tips

1) Increase RAM to 6 GB+. 2) Reduce server view-distance to 8 (server.properties). 3) Pre-generate chunks with the "Chunky" plugin. 4) Use /spark profiler to check which mods consume the most tick time. With Mado Hosting, all servers run on NVMe SSDs with dedicated CPU cores – eliminating hardware as a bottleneck.

Rent Celerium Server

Start your own server with automatic modpack installation.

Recommended RAM:
6 GB(min. 4 GB)
From 8.00 / month
Create Server Now
1-Click Modpack Install
NVMe SSD Storage
DDoS Protection included
Automatic Backups

Details

License
MIT License
Server-side
Required
Client-side
Required

Supported Versions

1.21.111.21.101.21.81.21.71.21.61.21.51.21.4

Start your Celerium Server now

From €8.00/month with 6 GB RAM for the best performance.

Configure Server →