InvAlert
InvAlert is a Fabric utility that warns the player with a sound and an on-screen message when the inventory is nearly full.
What it does
InvAlert watches the inventory and fires a one-shot warning the moment free space drops to three slots or fewer, so a player who keeps mining does not silently lose drops when the bag fills up. The check covers the 36 main inventory slots, which include the hotbar and the backpack, while armor and off-hand slots are left out because picked-up items never go there. A short pling sound and an action-bar message above the hotbar announce the warning, even when the player is looking elsewhere.
A persistent badge in the top-left corner of the HUD shows the number of free slots. The badge turns red and reads Inventory FULL when no slots remain, and it disappears as soon as a slot is freed. The warning fires again only after free space drops further, so it does not repeat while the player is managing items. The V key toggles the alert on or off, and an action-bar confirmation states the current setting.
Installation is client only: the mod needs Fabric API and nothing has to be installed on the server, which can be vanilla. InvAlert is published for Fabric alone, for 1.21.8, 1.21.9, 1.21.10 and 1.21.11, and the latest file is 1.0.0 for 1.21.11, released under the MIT License. The mod is not open source.
Key features
One-shot inventory warning
A sound and an action-bar message announce when free slots drop to three or fewer, then do not repeat until more space is used.
Free-slot badge
A HUD badge in the top-left corner shows the number of free slots and turns red with Inventory FULL at zero.
Main inventory tracking
The 36 main inventory slots, hotbar and backpack included, are counted, while armor and off-hand slots are excluded.
Toggle key
The V key switches the alert on or off, and an action-bar confirmation shows the state that is now active.
Gallery
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
Use cases
Who it’s for: Players who gather resources over long stretches and want a clear signal before a full inventory causes items to be lost.
How it compares
Client Side Action Bar is a client-side Fabric mod for 1.21.11 under the MIT License, and it is not open source. Hotbar Quickswap is client-side only and open source under the CC0 1.0 Universal license, with files for 1.21.10 – 1.21.11. LowDurabilityWarning is also client-side only and not open source, released under the MIT License for 1.21.1 – 1.21.11, so it covers the same range of versions as InvAlert.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| InvAlert | Fabric | 1.21.8 – 1.21.11 | Client-side only | 2026-06-01 |
| Client Side Action Bar | Fabric | 1.21.11 | Client-side only | 2026-05-06 |
| Hotbar Quickswap | Fabric | 1.21.10 – 1.21.11 | Client-side only | 2025-12-24 |
| LowDurabilityWarning | Fabric | 1.21.1 – 1.21.11 | Client-side only | 2026-06-08 |
Questions
Does InvAlert need Fabric API?
Does InvAlert have to be installed on the server?
Which game versions does InvAlert support?
In the catalog
InvAlert is one of 36,990 Utility mods on ModsFinder, and one of 25,772 Utility mods for Fabric. 19,862 mods support Minecraft 1.21.11.
More from kvapilvaclav0
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What the author says
InvAlert watches your inventory and warns you the moment free space runs out. No more strip-mining a vein only to realize half the cobble fell on the floor — the moment your bag drops to a few free slots, you hear it and see it.
Official listing
- Modrinth page
- modrinth.com/mod/invalert
- Owner
- kvapilvaclav0
- Published
- 2026-06-01
- Updated on Modrinth
- 2026-06-01
- Facts verified
- 2026-10-15