Quad Hotbar

Modified double hotbar mod that expands the HUD for more than 2 rows of hotbar.
Currently supports Minecraft 1.21.9–1.21.11

Quad Hotbar is a fork of the Double Hotbar mod, inspired by Multi Hotbar, Hot Baaaar, and Hysk LongHotbar.
It retains all original Double Hotbar features while adding a new 2×2 quad hotbar layout – essentially two double hotbars side by side, giving you 18 visible inventory slots at the bottom of the screen.

Important
This mod does not actually expand your hotbar or inventory capacity. It only makes extra inventory rows visible and easier to manage.
It is a client‑side only mod; no server installation is required.

Features

1. Quad Hotbar Layout – Four inventory rows are shown in two columns (left/right).
2. Smart Scrolling – Mouse wheel scrolls through all 18 bottom slots. Moving from left (slots 0–8) to right (slots 9–17) automatically swaps your real hotbar with the bottom inventory row.
3. Keybinds
   • Number keys 1–9 select the left bottom row; Ctrl + 1–9 select the right bottom row.
   • Double‑tap a number (or Ctrl + double‑tap) swaps that single slot with the corresponding slot above.
   • The swap key (default R) exchanges entire rows.
4. All original Double Hotbar features – hold‑to‑swap, double‑tap window, sound effects, etc. remain fully functional.

Layout

Top left: inventory[18..26] | Top right: inventory[9..17]
(Bottom left: hotbar (0..8) | Bottom right: inventory[27..35]) or (Bottom left: inventory[27..35] | Bottom right: hotbar (0..8))

The active row (where the selection highlight appears) switches dynamically between left and right as you scroll or use number keys. When crossing the border, the entire real hotbar is swapped with the bottom inventory row automatically.

Default Controls

You can change all keybindings in the Options → Controls menu. The modifier key used together with 1–9 and R is its own separate binding (Quad Hotbar Modifier Key).

Installation

1. Install Fabric Loader for Minecraft 1.21.9–1.21.11.
2. Install Fabric API and Cloth Config API.
3. Place the Quad Hotbar .jar file into your mods folder.
4. Launch the game. If you have Mod Menu, you can access the configuration screen directly in-game.

Configuration

The mod uses Cloth Config to provide an in‑game config screen (Mod Menu recommended) which has all configurables settings from original Double Hotbar mod. You can also manually edit config/double_hotbar.json(It shares the same config file with the original double hotbar mode).
Key options:

• quadHotbar – Enable/disable the 2×2 quad layout.
• inventoryRow – Which inventory row to show in double‑bar mode.
• shift – Vertical position of the extra hotbars.
• renderCrop – Crop height of the secondary hotbar background.
• holdToSwap / holdToSwapBar – Control the R key behaviour.
• allowDoubleTap / doubleTapWindow – Enable and configure double‑tap swapping.
• wooshVolume – Volume of the swap sound.
• reverseBars – Swap main hotbar and extra row positions.
• useSwapForHotbar – Use SWAP instead of PICKUP for certain exchange.