If you’ve ever been frustrated by how Finder handles default applications—especially when trying to assign different apps for viewing versus editing, or dealing with obscure developer file formats—I built UTIdefaults to fix that.
It’s a lightweight, fully native macOS utility designed to inspect, search, and manage system-wide file associations by UTI (Uniform Type Identifier) and MIME type in one centralized interface. No more right-clicking files one-by-one in Finder to click "Change All".
💡 Why I built it
macOS handles file associations under the hood using UTIs, but standard system settings don't expose these controls easily. Whether you're a developer needing specific editors for niche source code formats, or a power user who wants precise control over document handlers (or wants to set a safe "Do Nothing" action for risky file types), UTIdefaults gives you direct control over the system defaults database.
⚡ Key Features
- Centralized Management: Search and manage file types by extension, format name, UTI, or MIME type.
- Dual App Assignment: Set separate Viewer and Editor apps for individual file types.
- Flexible Modes: Switch between Standard (for everyday users) and Advanced modes (for deep UTI inspection).
- Granular Visibility: Filter UTIs by Preferred MIME, Selectable, or Show All to keep things clean or go deep into system definitions.
- "Do Nothing" Handler: Assign a safe dummy handler to block specific file types from opening automatically.
- Native & Lightweight: Built 100% in SwiftUI with a multithreaded architecture. Universal Binary optimized for Apple Silicon and Intel.
📋 System Requirements
- macOS 15.6 or later, Apple Silicon and Intel
🌐 Links & Downloads
I’d love to hear your feedback, thoughts, or feature requests!
- Mac App Store: Download on the Mac App Store
- Official Website: www.fiod3s.eu
- itch.io: fiod3s.itch.io/utidefaults
Let me know what you think!
Source: r/MacOS · by /u/Gold_Equipment1922