LiveMarkdown

LiveMarkdown is the sibling of LiveMarkup: a client-side Markdown editor with an instant preview that also renders math (KaTeX) and diagrams (Mermaid). No backend, no account, no build pipeline to babysit.

Why the math and diagrams matter

Plain Markdown preview is a solved problem. The reason LiveMarkdown exists is the two things most quick previewers skip: LaTeX math via KaTeX and diagrams via Mermaid, both rendered in the browser as you type. That’s the common case for the kind of writing I actually do — a README with a formula in it, a note with a sequence diagram — and it’s exactly the case where you otherwise end up committing, pushing, and waiting for a CI render just to check whether the equation lines up.

Keeping KaTeX and Mermaid client-side is a deliberate trade. The alternative — a server that renders math and diagrams — buys nothing here and costs a service to run, a queue to manage, and a bill that eventually argues for shutting the tool down. Client-side, the preview is instant and the whole thing stays a static file that runs indefinitely.

Like its sibling, it’s an exercise in finishing small things well — choosing a tight scope, shipping it, and keeping it alive with no infrastructure left to fail.