Unfold

The second major feature group is source code preview with syntax highlighting. Unfold supports a vast array of programming languages and configuration file types, displaying them with clean, color-coded syntax that makes code easier to read and understand at a glance. Users can adjust the font size for better readability on different displays and toggle line numbers on or off for precise reference. Text within the preview can be selected and copied directly, which is essential for quickly grabbing code snippets without opening a full editor. This feature is invaluable for developers who need to review pull requests, inspect config files, or look at logs without launching an IDE. The syntax highlighting is applied automatically based on file extensions, covering languages like Python, JavaScript, JSON, YAML, and many more. It transforms Quick Look from a simple text viewer into a lightweight code inspection tool.

The third feature group includes previews for Markdown, Mermaid diagrams, and ebooks. Markdown files are rendered as formatted documents complete with a Table of Contents, making it easy to navigate long READMEs or notes. Mermaid diagrams are displayed as interactive vector graphics that support zooming and panning, allowing users to examine complex flowcharts, sequence diagrams, and Gantt charts directly in Quick Look. Ebooks and comic archives (CBR and CBZ) are also supported, with a Table of Contents for navigating chapters or issues. This eliminates the need to open separate ebook readers or comic viewers just to preview a file. For writers, engineers, and documentation readers, these capabilities mean instant access to formatted content and visual diagrams without leaving the file manager. The rendered previews are faithful to the intended layout, preserving the original formatting.

Unfold works by integrating directly into macOS's Quick Look framework. When a user selects a file and presses the space bar, the system calls Unfold's preview generator instead of the default one. It then processes the file according to its type: for archives, it reads the file table without extracting; for source code, it applies syntax highlighting using a built-in parser; for Markdown, it renders the document to HTML; for Mermaid, it compiles the diagram into an SVG; and for ebooks, it extracts metadata and formatted text. The entire process is instantaneous, leveraging macOS's native capabilities. No additional background processes are required, and Unfold respects system security permissions. The result is a seamless, integrated experience that feels like a natural extension of the operating system. Users can quickly cycle through multiple files using the arrow keys while in Quick Look, enabling efficient batch inspections.

Concrete use cases include a developer browsing a code repository on GitHub or locally; with Unfold, they can quickly preview folder structures, read README files rendered with proper formatting, inspect source code with syntax highlighting, and even view Mermaid diagrams for documentation. A system administrator checking log files or configuration archives can instantly see contents without extraction. A writer or student reviewing Markdown notes can see the formatted output including headings and links. A comic book enthusiast can preview CBR and CBZ archives without opening a dedicated reader. A UI designer can view SVG files and other design assets. The outcome across all scenarios is reduced time, fewer application launches, and a more fluid file browsing experience. Users report significant boosts in productivity when navigating complex file systems, as they can make informed decisions about which files to open fully.

Unfold is targeted at macOS users running version 14 (Sonoma) or later. Its primary audience includes software developers, system administrators, technical writers, designers, and anyone who frequently previews multiple file types. The tool is installed via Homebrew (`brew install unfold`) or by direct download from the developer's website. It has no subscription or premium tiers; it is a simple utility that enhances an existing system feature. The lightweight footprint means it runs entirely on the local machine without internet dependency. In summary, Unfold turns the often-underutilized Quick Look into a powerhouse of file introspection, saving users countless interruptions throughout their day. By offering instant previews of over 149 file types with rich formatting and interactive features, it becomes an essential productivity tool for any serious macOS user.

Updated 2026-03-03