ClientReflex
by zxNoragami
ClientReflex is a Fabric client mod for players on laggy or high-ping servers, aiming to reduce disconnections and tighten the response of movement and attacks.
What it does
The mod changes how the client handles networking. A reconnect system attempts to rejoin a server after a brief connection drop, and a packet prioritization step sends movement, attacks and block placement ahead of less urgent traffic. Netty settings such as TCP NODELAY and KEEPALIVE are adjusted as well.
Several visual and input changes work from the measured ping. Render adjustments respond to latency, input smoothing and player interpolation soften jittery motion, and a safe visual prediction shows crystals, beds, anchors and TNT minecarts before the server confirms them. A Network HUD reports real-time ping and jitter statistics.
ClientReflex runs on the client alone, so servers and other players need nothing installed. It does not change what the server sees, and it is not designed as a cheat tool. Files are published for Fabric only, in two game versions: 1.21 and 1.21.4, with 1.0.2 for 1.21.4 as the latest. The code is open source under the MIT License.
Key features
Automatic reconnect
After a network drop, the client tries to rejoin the server without manual action, and the process is intended to keep short outages from ending a session.
Packet prioritization
Movement, attacks and block placement are sent ahead of other network traffic to make responses feel more immediate.
Network HUD
An on-screen display shows real-time ping and jitter statistics, so players can see the connection state while playing.
Input smoothing and prediction
Player interpolation smooths motion on high-latency connections, and visual prediction shows certain placed objects before the server responds.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
How it compares
Am I Lagging? is a Fabric client mod for 1.21.10 – 1.21.11, released under a Creative Commons Attribution Non Commercial 4.0 license. TwinPing is a Fabric client mod for 1.21.11 under All rights reserved. Both are client-side only, like ClientReflex, but they target newer game versions than the 1.21 – 1.21.4 range ClientReflex covers.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| ClientReflex | Fabric | 1.21 – 1.21.4 | Client-side only | 2026-01-27 |
| Am I Lagging? | Fabric | 1.21.10 – 1.21.11 | Client-side only | 2026-07-22 |
| TwinPing | Fabric | 1.21.11 | Client-side only | 2026-05-28 |
Questions
Does ClientReflex need to be installed on the server?
Which game versions does ClientReflex support?
Does ClientReflex change the game protocol or act as a cheat?
In the catalog
ClientReflex is one of 3,545 Optimization mods on ModsFinder, and one of 2,575 Optimization mods for Fabric. 17,979 mods support Minecraft 1.21.4.
More from zxNoragami
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What the author says
ClientReflex is a client-side mod for Minecraft that improves the multiplayer experience on servers with lag, high ping, or unstable connections. It optimizes how the client handles networking to reduce disconnections and make gameplay feel more responsive—without modifying the protocol or cheating. This mod only…
Official listing
- Modrinth page
- modrinth.com/mod/clientreflex
- Owner
- zxNoragami
- Published
- 2025-12-14
- Updated on Modrinth
- 2026-01-27
- Facts verified
- 2026-10-15