Skim — Markdown Viewer & Reader per Skim

Skim is a markdown viewer and reader for Firefox that renders .md files as clean, themed documents. Open a .md file from your computer or the web and Skim replaces the raw text with a formatted page: tables, task lists, images, and every README.

Built for how people read markdown today: AI coding agents write it constantly. Skim watches the file and auto-reloads the instant it's rewritten, turns YAML frontmatter into a readable header card, and adds a one-click "Copy for AI" button that hands the whole document back as clean markdown.

Full-featured: KaTeX math, mermaid diagrams, syntax-highlighted code with copy buttons, a scrollspy table of contents, light and dark themes, print/PDF export, encoding detection, and per-block RTL/LTR direction.

Skim collects no data: no telemetry, no analytics, nothing sent anywhere. Fully open source (MIT). Every feature is free. Issues: https://github.com/skim-md/skim