Stable Performance vr1.4.0

HeroSync

Latency compensation that makes high-ping gameplay feel local.

Stable · Released and maintained — r1.4.0 across 1.21–1.21.11 and 26.x. Built from 100 specification documents with a fully modular engine.

Why it exists

Purpose

Network latency makes otherwise-fine gameplay feel heavy. HeroSync removes that feeling client-side: your actions register instantly, then reconcile with the authoritative server — rolling back cleanly when the server disagrees.

Who it's for

Players on high-ping servers, everyone who wants a smoother-feeling game, and anyone who wants less perceived lag without server mods.

Key capabilities

Instant action registration

Player actions are registered locally at zero latency, so the game responds immediately.

Smart reconciliation

Outbound and inbound packets are observed and reconciled against server truth.

Clean rollback

A dedicated rollback engine reverses only what needs reversing when server state differs.

Broad version support

Shipped for every version from 1.21 to 1.21.11, plus experimental 26.x builds.

Features

Everything HeroSync does

9 features across 3 categories — all real, all working.

Latency Compensation 4 features

Instant Action Registration

Player actions are registered locally at zero latency.

Smart Reconciliation

Outbound and inbound packets are observed and reconciled against server truth.

Clean Rollback

A dedicated rollback engine reverses only what needs reversing.

Snapshot System

State snapshots for consistent rollback points.

Configuration 3 features

Feature Toggles

Individual features and the whole framework can be disabled.

Command Interface

/herosync exposes status, transactions, toggles, stats and debug overlay.

Debug Overlay

F3+L shows live latency compensation diagnostics.

Developer 2 features

HeroSyncAPI

Registration rules, packet classifiers, snapshot providers.

Compatibility Adapters

Adapters for common mod interactions.

Getting Started

How to use HeroSync

Download the HeroSync JAR for your Minecraft version.
Place it in your Fabric mods folder (Fabric API recommended).
Join any server — actions now feel responsive immediately.
Tune or disable features from the in-game settings screen.
Keep the JAR matched to your Minecraft version for best results.

View the full HeroSync tutorial →

Compatibility

Versions & loaders

Property	Value
Loader / platform	Fabric
Latest version	r1.4.0
Minecraft versions	1.21, 1.21.1, 1.21.2, 1.21.3, 1.21.4, 1.21.5, 1.21.6, 1.21.7, 1.21.8, 1.21.9, 1.21.10, 1.21.11, 26.1, 26.1.1, 26.1.2, 26.2

26.x builds are experimental (bundled-mappings).

Version history

Changelog

1.4.0

2026-08-01 Release Latest

Reconciliation & rollback refinements

Expanded version matrix to 1.21.11 and 26.x
Improved rollback precision
Developer API additions

Warning. 26.x builds use bundled mappings and are experimental

Warning. Check server rules — some communities restrict predictive clients

1.3.2

2026-06-12 Release

Stability pass

Fixed rollback edge cases on high-latency servers
Reduced per-tick cost

Fixed: crash when unloading a chunk during a pending rollback

Roadmap

Where it's going

Multi-version matrix

done

Real builds for 1.21–1.21.11 plus 26.x.

Per-version runtime adapters

Deepen runtime version adaptation beyond build-time matrices.

Hero Client module

later

First-class integration as a Hero Client module.

FAQ

Questions, answered

Does this work on servers without the mod?

Yes. HeroSync is client-side and requires nothing on the server.

Will it get me banned?

It compensates for latency like predictive clients do — it never fabricates confirmations. Always check server rules first.

Which versions are supported?

1.21 through 1.21.11 plus 26.x builds.

Does it change my actual ping?

No — it changes how lag feels by making your inputs register locally (0ms perceived delay).

Can I turn it off?

Yes — individual features and the whole framework can be disabled from config/herosync.json.

How much does it affect performance?

It keeps a sub-2ms per-client-tick performance budget.

Is there a command interface?

Yes — /herosync exposes status, transaction lists, registration toggles, stats, a debug overlay (F3+L) and reload.

Can other mods integrate with it?

Yes — it ships a developer API (HeroSyncAPI) with registration rules, packet classifiers, snapshot providers and compatibility adapters.

Compatibility & limitations

What to know

Compatibility. 26.x builds are experimental (bundled-mappings).

Status. Released and maintained — r1.4.0 across 1.21–1.21.11 and 26.x. Built from 100 specification documents with a fully modular engine.

Downloads

Get HeroSync

Pick the JAR matching your Minecraft version.

Fabric mod JAR + sources View Tutorial

Ecosystem

Part of something bigger

Every Hero Studios product is engineered to work with the rest of the ecosystem — one design language, one performance bar, one long-term vision. HeroSync belongs alongside these tools.