CaCl2Backup

CaCl2Backup is a free, MIT-licensed backup mod for Minecraft Java servers using Fabric. It can create backups on an interval, on a daily schedule, or when the server stops, and those triggers can be combined. The mod writes backups to temporary output, checks them with CRC verification, and publishes them atomically after validation. Automatic cleanup can use both a maximum backup count and a maximum age. Operators can create, list, restore, and delete backups with /backup commands; each command requires OP privileges. Restoring replaces the current world save. The configuration can be reloaded without restarting the server. The changelog describes restore safeguards including level.dat validation and rollback handling, as well as protections for path traversal and backup-name filtering. Installation instructions call for Fabric Loader and Fabric API, then placing the mod JAR in the server's mods folder. Listed requirements are Minecraft 26.0+ in the 26.x series, Fabric Loader 0.15.0+, Fabric API, and Java 25+. Backups are stored locally.

CaCl2Backup provides configurable local backups and full-world restore for Fabric servers. Check the stated version requirements and note that restoring replaces the active world save.

This mod suits operators of Fabric Minecraft Java servers who want scheduled or event-triggered local world backups. It requires the listed Minecraft, loader, API, and Java versions.

CaCl2Backup is a free, self-hosted backup mod for Minecraft Java servers running Fabric. It best fits server operators who want recurring local world backups and operator-controlled recovery. Its integrity and restore safeguards are a strength, but support is confined to Minecraft 26.x and restoration replaces the whole active world save.

Overview

This is a focused server-side tool: it backs up worlds to local storage rather than offering a general backup service or external storage destination. Interval, daily, and server-stop triggers can be combined, so operators can cover routine snapshots as well as planned shutdowns. Automatic cleanup can limit backups by both count and age, giving administrators a way to balance disk use against recovery history.

Backup creation is designed to avoid presenting an incomplete archive as ready: output is temporary until CRC verification succeeds, then published atomically. Restore checks level.dat and includes rollback handling for failed swaps, with recovery on a subsequent start after a failed startup. These protections are meaningful for world recovery, but they do not change the full-backup scope: a restore replaces the current world save rather than selectively recovering files.

Key features

• Combined backup triggers: Interval, daily schedule, and server-stop triggers can be used together. That suits operators who want scheduled coverage plus a copy when the server shuts down.
• Verified publication: Temporary output, full CRC verification, and atomic publication help ensure only validated backups are made available.
• Count- and age-based retention: Automatic cleanup can enforce both a maximum number of backups and a maximum age. Operators can limit local accumulation while retaining copies for a chosen period.
• Operator commands: Users with OP privileges can create, list, restore, and delete backups with /backup commands. This keeps management tied to server operator access, but is not a separate non-operator control surface.
• Restore safeguards: Restore validates level.dat; failed swaps have rollback handling, and preserved rollback worlds support recovery after startup failure. Restoring still replaces the active world save.
• Reloadable configuration: Configuration can be reloaded without restarting the server, useful when adjusting settings on a running service.
• Security fixes: The changelog reports Zip Slip path-traversal protection, backup-name path filtering, and a fix for a TOCTOU race condition.

Pricing

Free: free. The plan is the MIT-licensed Fabric server mod; there are no paid tiers or paid-plan trade-offs described. Its cost is zero, but it requires Minecraft 26.0+ in the 26.x series, Fabric Loader 0.15.0+, Fabric API, and Java 25+.

Platforms

CaCl2Backup is self-hosted and targets Minecraft Java servers using Fabric. Installation requires Fabric Loader and Fabric API, followed by placing the mod JAR in the server’s mods folder. Minecraft support is limited to the 26.x series at version 26.0 or later, with Java 25+ required. Those prerequisites make it unsuitable for other Minecraft editions, older Minecraft releases, or servers that do not use Fabric.

Who it's for

Choose CaCl2Backup if you run a compatible Fabric server and want free, local world snapshots with combined schedules, automatic retention, and full-world restore safeguards. Look elsewhere if you need external backup storage, backup scope beyond worlds, selective file restoration, or compatibility outside the stated Minecraft and Java requirements.

Pros and cons

Pros

• Flexible scheduling: Interval, daily, and server-stop triggers can be combined to cover routine and shutdown backups.
• Integrity and rollback measures: CRC verification and atomic publication protect backup readiness, while restore validation and rollback handling address failed world swaps.
• Useful retention controls: Count and age limits let operators manage local storage accumulation.
• No license fee: The free MIT-licensed mod has no paid tier to budget for.

Cons

• Narrow compatibility: Minecraft 26.x, Fabric, and Java 25+ requirements rule out many server setups.
• Local, worlds-only scope: It does not provide an external storage destination or wider server backup scope.
• Full-world restore only: Recovery replaces the active world save, so it is not suited to retrieving an individual file while preserving the rest of the current world.
• Operator-only commands: Every /backup command requires OP privileges.

Alternatives

Consider Minecraft Backup Software to compare more tools in this category. The specific alternatives below differ by platform, server type, or storage prerequisite:

• InstantBackup is another free, open-source Minecraft server mod, with Linux, macOS, Windows, and self-hosted platform coverage.
• Minecraft Backup is a free backup script for Minecraft servers on Linux, rather than a Fabric mod.
• BtrBack is a free Minecraft backup plugin for setups using a Btrfs subvolume.
• DriveBackupV2 is a free, MIT-licensed plugin for Bukkit-based servers and requires Java 8+.
• FastBack is a free Minecraft backup mod with Linux, macOS, and Windows coverage, distributed under GNU GPL version 2.
• FolderRewind is free and open source for Windows 10 and 11.
• Just Enough Backups is a free, open-source Fabric mod for server-side world backups, with Linux, macOS, and Windows coverage.
• ServerBackup is a free Minecraft server backup plugin for Linux and self-hosted platforms.

Verdict

CaCl2Backup is a strong fit for operators of Minecraft 26.x Fabric Java servers who want scheduled local world backups, clear retention limits, and guarded full-world recovery at no cost. Its verified backup publication and rollback handling are compelling for that narrow use case. Choose another tool if your server falls outside its requirements or you need external storage, broader backup scope, or selective restores.