Eslium Backport
by sz_co
Eslium Backport is a Fabric client mod that predicts the results of certain player actions before the server confirms them, to reduce the delay caused by ping.
What it does
Some actions, such as placing an end crystal or spawning a minecart on a rail, normally wait for server validation before anything appears on screen. Eslium Backport shows the expected result on the client straight away, then the server's answer takes over. The mod is a backport of the Eslium project, which predicts more actions on the client side in its newer form, and it is published for 1.16.5 and 1.21.11.
Prediction covers consumables, cooldowns, crystals, elytras, fireworks, minecart poses, weapon swaps, wind charges, throwables and placeable blocks, plus interactables, tools, combat, redstone anchors and placement. Each section shares the same base options, and the enabled servers, maxTime and maxDistance settings apply across sections where they are shown. Allowed servers can be listed so prediction only runs where the server owner permits it.
Eslium Backport requires Fabric API and works with Mod Menu for its settings screen. It is client-side only, so servers and other players do not need it. The code is released under the GNU Lesser General Public License v3.0 only and is open source, with source code publicly available. Files exist for 1.21.11 with the latest build 4.6.0, published on 2026-10-13.
Key features
Client-side action prediction
Actions such as placing crystals or spawning minecarts appear immediately on the client while the server validates them.
Per-section options
Consumables, combat, redstone and placement each have their own prediction section with shared base settings.
Ping compensation
The mod is intended to offset the visual delay caused by latency for the actions it predicts.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Optional 1
How it compares
Projectile Optimizer is client-side only, open source under the MIT License, and covers 1.21.4 – 1.21.11 on Fabric. Consumable Optimizer is also client-side only and open source under the MIT License, with Fabric builds for 1.20.5 – 26.3. Shikaru's Crystal Optimizer focuses on crystals, is client-side only, open source under the MIT License, and targets 1.21.11 – 26.2 on Fabric.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Eslium Backport | Fabric | 1.16.5 – 1.21.11 | Client-side only | 2026-10-13 |
| Projectile Optimizer | Fabric | 1.21.4 – 1.21.11 | Client-side only | 2026-05-21 |
| Consumable Optimizer | Fabric | 1.20.5 – 26.3 | Client-side only | 2026-10-10 |
| Shikaru's Crystal Optimizer | Fabric | 1.21.11 – 26.2 | Client-side only | 2026-09-20 |
Questions
Does Eslium Backport need Fabric API?
Does the server need Eslium Backport?
Which game versions does Eslium Backport support?
Can prediction cause bugs or trigger anticheat?
In the catalog
Eslium Backport is one of 3,545 Optimization mods on ModsFinder, and one of 2,575 Optimization mods for Fabric. 19,862 mods support Minecraft 1.21.11.
Similar mods
What the author says
Eslium is a project to predict more things client-side. For example, if you want to use a Crystal, you must wait for the server validation for it to appear. This mod fixes that and therefore compensates for the ping. When using any type of minecart on a rail, the spawn of the minecart is predicted
Official listing
- Modrinth page
- modrinth.com/mod/eslium-backport
- Owner
- sz_co
- Published
- 2026-08-09
- Updated on Modrinth
- 2026-10-13
- Facts verified
- 2026-10-15