ImproperUI
by ItziSpyder
With ImproperUI, a Fabric client gets scripted screens that players write in a CSS-like language instead of Java rendering code.
What it does
ImproperUI runs a custom scripting language whose syntax is inspired by CSS, though it is not fully identical. Scripts describe elements, their basic CSS-style properties and simple HTML-style structures, and the mod turns them into working in-game GUIs. The home screen of the mod is one example, with draggable and scrollable elements built from ImproperUI Script.
The mod is a Fabric library. Mods that want an ImproperUI panel reference the script file by its name, not by the path it sits at, and they register a callback when the panel is created. Script events use a CallbackHandler annotation with a parameter naming the event type to listen for. Five catalog mods, including Player Health Indicators (ANIMATED), Advanced Autoclicker and CrosshairTarget, require it. It runs on the client alone, and the code is released under the MIT License, so it is open source. Files exist for Fabric on 15 release versions, 1.20 – 26.2, with 26.2-0.0.8-BETA for 26.2 as the latest file.
Key features
CSS-style scripting
Screens are described with basic CSS properties and how they apply, so layout does not need Java rendering code.
HTML-style structures
Elements are nested in simple HTML-like structures that the script builds into a screen tree.
Callback handling
A CallbackHandler annotation with an event type parameter lets scripts respond to actions in the panel.
Config-bound sliders
A config key written as three parts joined by colons can drive a slider that sets and saves values in the config.
Gallery
Compatibility
Latest build for each game version and loader.
26.x4 of 4 versions with builds
1.21.x5 of 5 versions with builds
1.20.x6 of 6 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Required by 5 mods
Use cases
Custom settings screens
A mod author can build a panel with sliders and other controls that read and write config values.
Interactive overlays
Draggable and scrollable elements can be laid out in a script for panels that players move around.
Who it’s for: Mod developers who want to build in-game GUIs without writing rendering code in Java, and who are targeting Fabric.
How it compares
Peripheral is a client-side Fabric mod under the MIT License, open source, with files for 1.21 – 26.1.2. Hudifine is also client-side on Fabric and open source under the GNU General Public License v3.0 or later, but its files cover only 26.1.2 – 26.2. DFScript is client-side on Fabric, open source under the GNU Lesser General Public License v3.0 only, and published for 1.19 – 1.20.4.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| ImproperUI | Fabric | 1.20 – 26.2 | Client-side only | 2026-08-14 |
| Peripheral | Fabric | 1.21 – 26.1.2 | Client-side only | 2026-04-27 |
| Hudifine | Fabric | 26.1.2 – 26.2 | Client-side only | 2026-06-18 |
| DFScript | Fabric | 1.19 – 1.20.4 | Client-side only | 2024-05-21 |
Questions
Does ImproperUI need Fabric API?
Does ImproperUI have to be installed on a server?
Which game versions does ImproperUI support?
In the catalog
ImproperUI is one of 3,514 Library mods on ModsFinder, and one of 2,348 Library mods for Fabric. 13,894 mods support Minecraft 26.2.
More from ItziSpyder
Similar mods
What the author says
ImproperUI's syntax is highly inspired by CSS (Cascading Style Sheets), thought it is not entirely identical. Here is an example of how ImproperUI can be used in a mod!
Official listing
- Modrinth page
- modrinth.com/mod/improperui
- Owner
- ItziSpyder
- Published
- 2024-05-07
- Updated on Modrinth
- 2026-08-14
- Facts verified
- 2026-10-15