I work with a lot of Markdown and config files. macOS Quick Look is my go-to for quickly checking file contents, but it kept showing me raw Markdown syntax and blank screens for SQLite. I ended up building my own QuickLook extension.

It renders Markdown with GFM tables, KaTeX math, Mermaid diagrams. Highlights 190+ languages. Shows CSV as a sortable table, SQLite with table switching, diffs with color-coded lines. ZIP/TAR you can browse without extracting.

The thing I'm most happy with in the latest version is live reload. I can edit a Markdown file, save, and the preview just updates. No closing and reopening Quick Look. I used a native CoreGraphics renderer for Mermaid (BeautifulMermaid) so the diagrams update without any flicker.

Everything runs offline and sandboxed. No analytics.

Free trial, no signup needed. macOS 14+.