(Forge) Item NBT Viewer (Tooltip) (+ Slot Numbers)
Every seasoned Minecraft player knows that beneath the surface of a simple diamond sword or a shulker box lies a complex web of data. This data, known as NBT (Named Binary Tag), controls everything from enchantments and custom names to the contents of containers. For modders, map makers, and curious tinkerers, accessing that information used to mean external editors or cumbersome commands. Now, with the (Forge) Item NBT Viewer (Tooltip) (+ Slot Numbers) add-on, all that hidden detail becomes instantly visible right inside your inventory tooltips.
What Makes This NBT Viewer Essential for Forge Players
This mod is a direct Forge alternative to the popular NBT Tooltip mod, but it brings its own unique formatting and control scheme. Once activated, it overlays a clean, scrollable readout of an item stack’s entire NBT structure directly within the tooltip box. No more guessing what tags a custom item holds or why a datapack isn’t working—you can inspect every tag, every list, and every compound right from your hotbar. Additionally, the mod appends a separate line showing the exact slot number the item occupies, a small but invaluable feature for inventory management and scripting.
Key Features at a Glance
- Full NBT tree display – view all tags, including nested compounds and lists, in a human-readable format.
- Scrollable tooltip – use key bindings to scroll through long NBT data without it overflowing off-screen.
- Adjustable view size – resize the NBT panel on the fly to fit your screen or preference.
- Slot number indicator – instantly see which inventory slot an item is in, perfect for redstone and command block projects.
- Fast scrolling – a secondary key mapping lets you jump through large data sets quickly.
- Lightweight and focused – no bloat, no unnecessary features; it does one job and does it well.
How to Enable and Use the NBT Tooltip
Before the mod can work its magic, you need to turn on Minecraft’s advanced tooltips. Simply press F3 + H while in-game. You’ll see a confirmation message in chat. From that moment, hovering over any item will reveal its NBT data in a structured format. The default key to scroll the NBT view is N (hold it and use the mouse wheel), while M adjusts the panel size. You can rebind these in the controls menu under the “Item NBT Viewer” category. For rapid scrolling, hold the assigned fast-scroll key (check the screenshot in the mod’s documentation) and scroll—ideal for items with hundreds of tags like complex backpacks or custom machines.
Supported Minecraft Versions and Loader
The (Forge) Item NBT Viewer (Tooltip) (+ Slot Numbers) was originally crafted for Minecraft 1.14.4 and has been successfully ported to 1.17.1. The developer has expressed confidence in maintaining compatibility with future releases, so you can expect updates for newer versions of the game. As the name implies, this mod is built exclusively for the Forge mod loader. If you’re running Fabric, you’ll need to look for a Fabric-specific alternative, but for Forge users this is a top-tier choice.
Installation Guide: How to Install the Mod
Getting the mod up and running is straightforward. First, ensure you have the correct version of Forge installed for your Minecraft client. Then follow these steps:
- Download the (Forge) Item NBT Viewer (Tooltip) (+ Slot Numbers) jar file for your Minecraft version from a trusted source.
- Locate your Minecraft installation folder and open the
modsdirectory. If it doesn’t exist, create it. - Place the downloaded jar file into the
modsfolder. - Launch Minecraft with the Forge profile. The mod will load automatically.
For those who prefer a streamlined experience, the foxygame.net launcher offers a one-click install option for (Forge) Item NBT Viewer (Tooltip) (+ Slot Numbers), automatically matching the correct mod version to your game instance and keeping it updated without manual file management.
Why Slot Numbers Matter More Than You Think
The addition of slot numbers might seem minor, but it’s a game-changer for technical players. When you’re writing command block contraptions that reference specific inventory slots, or debugging a mod that interacts with player inventories, knowing the exact slot index (0-35 for hotbar and main inventory, 100-103 for armor, etc.) saves time and prevents errors. The mod displays this number as a simple integer right below the item name, so you never have to count slots again.
Perfect for Mod Developers and Pack Makers
If you’re developing a mod or assembling a custom modpack, this tool is indispensable. You can quickly verify that your custom items have the correct NBT structure, check that loot tables are generating the intended tags, and ensure compatibility between mods that share NBT data. The scrollable view means even deeply nested tags—common in tech mods like Mekanism or Create—are fully readable. The mod’s developer originally created it by request from the community, filling a gap for a Forge-compatible NBT viewer that didn’t compromise on usability.
Customization and Controls
All key bindings are fully configurable via the standard Minecraft controls menu. Look for the “Item NBT Viewer” category to adjust scroll, resize, and fast-scroll keys. The mod also respects the game’s GUI scale, so the tooltip remains crisp at any resolution. If you ever need to disable the NBT display temporarily, simply toggle off advanced tooltips with F3+H again—the slot number line will remain visible as long as the mod is installed, giving you a persistent inventory reference.
Final Thoughts
The (Forge) Item NBT Viewer (Tooltip) (+ Slot Numbers) is a must-have utility for anyone who wants to peek under the hood of Minecraft’s item system. It’s lightweight, easy to install, and brings a level of transparency that benefits both casual explorers and hardcore modders. Whether you’re troubleshooting a custom map, learning how NBT works, or just satisfying your curiosity, this mod delivers exactly what it promises. Download it today and turn every tooltip into a window of information.