MDForge

Write Markdown. See Markdown.

A live-preview Markdown editor for VS Code — Typora-like editing, GitHub-style rendering — where the .md file stays exactly what you typed.

Why

Most WYSIWYG Markdown editors keep a model of your document and write it back out when you save. Move one word, and the file comes back reformatted: emphasis markers swapped, lists renumbered, a diff nobody can read.

MDForge has no model. The editor's document is the Markdown text, and rendering is done by hiding and styling characters in place. Type one character, and git sees one character.

• Your file, untouched — no re-serialization, no reflow, no surprises.
• The default editor for notes, while git comparisons keep opening in VS Code's own diff editor, red and green intact.
• MIT, no paid tier, no telemetry, no account.

What you get

Editing that renders as you type

Headings, emphasis, code, quotes, links, images and lists render in place. Put the caret on something and its raw Markdown comes back, so nothing is ever hidden from you. / opens a block menu, a selection raises a formatting bubble, and the left margin carries a handle to drag a block (a heading takes its whole section), a chevron to fold it, and a click to select it.

Task lists are clickable, with a third state of our own: [ ] → [~] in progress → [x].

Tables you can actually use

Cells render their content — images, inline Markdown, even filtered raw HTML — and you edit one cell at a time without opening the whole table: hover, ✎, type, Entrée. Column borders are draggable; the widths are stored in an HTML comment above the table, which every other Markdown renderer ignores, so the file stays portable.

Diagrams, maths, code

Mermaid diagrams are drawn at the width of your text column, with six themes; KaTeX renders $inline$ and $$block$$ maths; fenced code is highlighted per language, with a picker to change it.

Metadata that reads like metadata

YAML frontmatter becomes a card: the title as a heading, every other key as a chip. Click a chip to edit that one property — tags get a chip editor that completes on the tags already used in your workspace, scanned once and cached.

What changed since your last commit

MDForge paints its own quick-diff margin: green for an addition, blue for a change, a red wedge where something was cut. It follows the live text, so an unsaved edit shows up as you type, and it updates on its own when you commit, stage or switch branch.

Search that lands where you clicked

Click a Ctrl/Cmd+Shift+F result and the note opens on the match, with the term you searched for highlighted throughout and MDForge's own search panel holding it — F3, Entrée or next walk the occurrences.

VS Code hands a custom editor neither the result you clicked nor the query (vscode#289785); MDForge recovers both from the Search view. A note with a single match, or a regex search, marks the line instead of the word.

And the rest

• Paste from the web — HTML becomes Markdown, images are downloaded next to your note, and MathJax formulas come back as LaTeX.
• Wikilinks [[note]], clickable; footnotes with a popup that files the definition in the right section and numbers it for you.
• GitHub alerts (> [!NOTE], > [!WARNING]…) with a type dropdown on any quote.
• Assets — paste or drop an image and it is saved beside the note, named after it; localize remote images, rename a note and its assets follow, move or delete a note with them.
• Outline panel, foldable, and a presentation mode for reading.
• Linter diagnostics from markdownlint and friends, shown in place, with quick fixes.
• Reformat on demand — collapse extra blank lines, put each paragraph back on one line — never behind your back, never per keystroke.
• Justified text, line numbers, and a page-width toggle.

Slide decks

Files named *.marp.md open in the plain text editor, not in MDForge — that is what Marp users expect, since Marp renders its deck in VS Code's built-in Markdown preview. It is only a default: put "*.marp.md": "mdforge.editor" in workbench.editorAssociations to edit decks here instead, and open the deck preview to the side from the Command Palette (Markdown: Open Preview to the Side).

Settings

Shortcuts

Requirements

VS Code 1.133 or later. That is what lets MDForge be the default editor for your notes without taking over the diff editor — the two priorities became separate in 1.133.

The quick-diff margin uses the built-in Git extension; without it, or outside a repository, the margin is simply empty.

Known limits

• No red/green inside the diff editor. A webview editor only ever receives its own side of a comparison, so MDForge cannot render a diff. Git comparisons therefore open in VS Code's native diff editor — and two buttons in its title bar open either side in MDForge. The quick-diff margin covers the single-file case. This is waiting on a proposed VS Code API (#333400).
• [~] is an MDForge convention. GFM only has [ ] and [x]; other tools will show [~] as plain text.
• Very large notes (thousands of lines) rebuild their decorations on every selection change. Normal notes are unaffected.

Contributing

npm install
npm run build     # extension (tsc) + webview bundle (esbuild)

Then F5 for an Extension Development Host. CLAUDE.md is the project's shared memory — architecture, how each feature works, and the CodeMirror lessons learned the hard way; SPEC.md holds the roadmap. Issues and pull requests welcome.

Built with

CodeMirror 6 · Mermaid · KaTeX · Turndown — all MIT.

License

MIT © 2026 tribaud