21-21 Client-Side

Name: 21-21 Client-Side
Price: 8 EUR
Author: ivurie

For the 21-21 modded server. Currently only intended for Fabric 1.21.10

by ivurie

156 Downloads

0 Followers

fabricMC 1.21.10lightweightmultiplayeroptimization

Rent 21-21 Client-Side Server

About this Modpack

Intended only for Fabric 1.21.10

Notice: No current plans on updating to a different version.

For the 21-21 private modded server, client-side download only. This modpack is focused on simple optimization, customizablity, quality of life tweaks, minor visual enhancements, and fun in a multiplayer world/server.

Labeled as client-side because it is meant to be paired with the server-side modpack. It's been made for a private modded server called 21-21, but people outside the server that like this modpack and wish to use it for their own server may find a list of the server-side mods and link to the server-side modpack at the bottom of the description.

21-21 contains these mods for client-side:

[EMF] Entity Model Features by Traben
[ETF] Entity Texture Features by Traben
3D Skin Layers by tr7zw
Anvil Too Expensive Fix by Eposs
AppleSkin by squeek502
Architectury API by architectury
Balm by BlayTheNinth
Better Mount HUD by Lortseam
Better Statistics Screen by TheCSDev
Better Tab by Fy17
BetterF3 by TreyRuffy
Capes by caelthecolher
Chat Heads by dzwdz
Chunks fade in by kerudion
Cloth Config API by shedaniel
Clumps by jaredlll08
Collective by Serilum
Continuity by PepperCode1
Cut Through by Fuzs
Debugify by isxander
Durability Tooltip by SuperMartijn642
Dynamic FPS by juliand665
Elytra Trims by KikuGie
Entity Culling by tr7zw
Fabric API by modmuss50
Fabric Language Kotlin by modmuss50
FerriteCore by malte0811
Forge Config API Port by Fuzs
Gamma Utils (Fullbright) by Sjouwer
ImmediatelyFast by RaphiMC
Inventory Profiles Next by blackd
Jade by Snownee
LambDynamicLights by LambdAurora
libIPN by blackd
Lithium by CaffeineMC
Mod Menu by Terraformers
Model Gap Fix by MehVahdJukaar
ModernFix-mVUS by Coredex
More Chat History by JackFred
More Culling by FX
Mouse Tweaks by YaLTeR
No Chat Reports by Aizistral
Open Parties and Claims by thexaero
OptiGUI by opekope2
Particle Rain by PigCart
Puzzles Lib by Fuzs
Reese's Sodium Options by FlashyReese
Shulker Box Tooltip by MisterPeModder
Silk by jakobkmar
Simple Voice Chat by henkelmax
Sit by bl4ckscor3
Sodium by CaffeineMC
Sodium Extra by FlashyReese
Sound Physics Remastered by henkelmax
SuperMartijn642's Config Lib by SuperMartijn642
TCDCommons API by TheCSDev
Text Placeholder API by Patbox
Veinminer by Miraculixx
Veinminer Enchantment by Miraculixx
Xaero's Minimap by thexaero
Xaero's World Map by thexaero
YetAnotherConfigLib by isxander
Your Options Shall Be Respected (YOSBR) by shedaniel
Zoomify by isxander

^ As of the latest version of the modpack--some are required for server-side as well and will be included in the server-side list.

21-21 requires and recommends these mods for server-side:

Almanac by frikinjay
Anvil Restoration by Serilum
Anvil Too Expensive Fix by Eposs
AppleSkin by squeek502
Architectury API by architectury
Balm by BlayTheNinth
Better Statistics Screen by TheCSDev
Cloth Config API by shedaniel
Clumps by jaredlll08
Collective by Serilum
Concurrent Chunk Management Engine (Fabric) by ishland
Debugify by isxander
Elytra Trims by KikuGie
Fabric API by modmuss50
Fabric Language Kotlin by modmuss50
FerriteCore by malte0811
Forge Config API Port by Fuzs
Jade by Snownee
Let Me Despawn by frikinjay
Lithium by CaffeineMC
ModernFix-mVUS by Coredex
NetherPortalFix by BlayTheNinth
No Chat Reports by Aizistral
Open Parties and Claims by thexaero
Puzzles Lib by Fuzs
Silk by jakobkmar
Simple Voice Chat by henkelmax
Sit by bl4ckscor3
Sleep by Jodek
Sound Physics Remastered by henkelmax
SuperMartijn642's Config Lib by SuperMartijn642
TCDCommons API by TheCSDev
Text Placeholder API by Patbox
Veinminer by Miraculixx
Veinminer Enchantment by Miraculixx
Very Many Players (Fabric) by ishland
Xaero's Minimap by thexaero
Xaero's World Map by thexaero
YetAnotherConfigLib by isxander

^ These are not included in this modpack as it's intended for client download for members of the 21-21 server. If you are not a part of the server but would like to use the modpack yourself on a world/server, there's a link right below to the server-side modpack

Link to server-side Modrinth modpack: https://modrinth.com/modpack/21-21-server-side

Available Versions

21-21 Client-Side 1.1.0release

MC 1.21.10fabric123 downloads

December 13, 2025

21-21 Client-Side 1.0.0release

MC 1.21.10fabric31 downloads

November 28, 2025

How to Set Up a 21-21 Client-Side Server

Order Server

Choose at least 4 GB RAM (6 GB recommended for 21-21 Client-Side). Based on player count: per 8 players.

Install Modpack in Dashboard

Open the modpack browser in the dashboard, search for "21-21 Client-Side" and click "Install". The fabric loader and Minecraft 1.21.10 are configured automatically.

Start Server & Play

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

Frequently Asked Questions

21-21 Client-Side 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 21-21 Client-Side 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 21-21 Client-Side without conflicts?

Yes, but check compatibility: only use mods for the same loader (fabric) and same Minecraft version (1.21.10). 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.

21-21 Client-Side 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.