Why notes should be markdown files

Your notes will outlive the app you wrote them in. Every proprietary note format in history has eventually needed a converter, and every converter loses something. Plain text does not have this problem, because the file is the content.

Markdown adds just enough convention on top — headings, emphasis, lists, links, code — to be structured without stopping being readable when nothing renders it.

It is worth being honest about the limits, because the format is often oversold. Markdown has no good story for complex tables, precise layout, handwriting, or anything spatial. There is no single standard — CommonMark, GFM and various dialects disagree on details — so a document can render differently in two tools. And extensions for maths, diagrams and callouts are conventions rather than specification, so portability is partial.

If your notes are mostly handwritten, mostly visual, or mostly structured records, markdown is the wrong hammer and something like OneNote, Heptabase or a database tool will serve you better.

Raw markdown with a rendered preview beside it is the old model and it splits your attention. Live preview — where syntax hides as you write and reveals when your cursor enters it — is what makes markdown feel like writing rather than marking up.

Nodum uses CodeMirror 6, the same editor engine Obsidian uses, with three modes: live preview, raw source, and reading view, cycled with ⌘E. Headings size themselves, emphasis renders, task checkboxes are clickable, code fences highlight, and the syntax reappears exactly where you are typing.