Markdown, diagrams & preview

Editora renders Markdown natively (no embedded browser) and gives Markdown files a few editing aids on top.

Live preview

Markdown files get an IntelliJ-style 3-mode view from a floating control at the top-right of the editor:

Editor: just the source.
Split: source on the left, preview on the right.
Preview: the rendered page only.

The preview is built from CommonMark + GFM and aims to match GitHub: real task-list checkboxes, inline-code pills, underlined headings, tables, and images (local and remote, including SVG badges). It updates live as you type, follows the active theme or its own light/dark toggle, and remembers its mode per file.

Beyond GFM it also renders YAML front matter (as a metadata block), footnotes, heading anchors, and ++inserted++ text, and the Structure tool window shows the document’s #…###### heading outline for quick navigation.

Zoom with the − / + control or Ctrl+wheel. In Preview mode, Space / PageDown and Backspace / PageUp scroll the page, and a right-click menu offers Select All, Copy, Export to PDF, and Print. A link in the preview is clickable, it shows a hand cursor and opens in your system browser.

The format bar

Select text in a Markdown file and a small format bar appears above the selection with bold, italic, strikethrough, inline code, link, list, and a heading level picker. The same actions are commands with Emacs markdown-mode chords:

Action	Command	Default key
Bold / italic / strike / code	`markdown.bold` …	`C-c C-s b/i/s/c`
Insert link	`markdown.link`	`C-c C-a l`
Promote / demote heading	`markdown.headingPromote` / `Demote`	`C-c C-h p` / `d`
Open link under caret	`markdown.openLink`	`C-c C-o`
Reflow table	`markdown.reflowTable`	`C-c C-s t`

List and quote continuation happens automatically on Enter. Ctrl/Cmd-click opens a link. The format bar can be turned off in Settings → Editor.

You can also insert a table of contents (markdown.toc) and a task list (markdown.taskList, C-c C-s k).

Tables

Beyond the format bar’s reflow, the right-click Table submenu (and the palette) edits the table under the cursor: insert a table (markdown.insertTable), add / delete rows and columns (markdown.tableAddRow / tableAddColumn / tableDeleteRow / tableDeleteColumn), and Tab moves between cells with Enter adding a row.

Tables interoperate with CSV and spreadsheets:

Convert to and from CSV (markdown.tableToCsv / markdown.tableFromCsv, delimiter auto-detected, RFC-4180 quoting).
Export the table to a CSV, Excel (.xlsx), or ODF (.ods) file (markdown.tableExportCsv / tableExportExcel / tableExportOds).

See CSV & TSV for editing data files directly.

Linting, math, and editing aids

Linting: a broad slice of the markdownlint rule set (heading-level increment, hard tabs, blank-line and spacing rules, bare URLs, trailing punctuation, first-line H1, and more) shows as inline squiggles with hover messages, scrollbar and minimap stripes, and a Markdown Lint tool window. Auto-fix (markdownLint.fix) corrects the safely-mechanical issues in one undoable edit. Turn individual rules off in Settings → Markdown or with markdownLint.toggleRule, use inline  comments, or a nearest .markdownlint.json. On by default; toggle with View: Toggle Markdown Lint.
LaTeX math: render inline $…$ and display $$…$$ math in the preview (and in PDF export) via JLaTeXMath, with GitHub-style delimiter rules so prose dollar amounts are left alone. Off by default (Settings → Editor → Render LaTeX math).
Image paste and drag-drop: paste an image from the clipboard, or drop image files onto a saved Markdown buffer, and the file is written into a sibling assets/ folder with the ![](…) link inserted.
Smart link paste: paste a URL over a selection to wrap it as [selection](url).
Table editing: Tab / Shift-Tab move between pipe-table cells, and Enter on the last row adds a row, reflowing as you go.

Mermaid diagrams

Mermaid renders inline. A fenced ```mermaid block in Markdown becomes a diagram in the preview, and standalone .mmd files get the same 3-mode preview.

Mermaid is off by default. Enable it in Settings → Mermaid and point it at the mmdc (mermaid-cli) command, with optional maid for linting (a blank field uses npx). Rendering uses mmdc and is cached per diagram; .mmd files get live linting that underlines errors with precise line and column messages. Export a diagram to SVG, PNG, or PDF with mermaid.export.

HTML live preview

Beta

On any .html / .htm / .xhtml file, a floating globe button opens it in a detected browser (Safari, Chrome, Firefox, Edge, or the system default), served over a tiny loopback-only web server with live reload as you type. Sibling CSS, JS, and images load from disk.

It’s off by default; enable it in Settings → HTML Preview. The file must be saved so its assets resolve, and remote (SFTP) files are excluded. Commands: htmlPreview.open and htmlPreview.openIn (pick a browser).

Export and print

Export code to a syntax-highlighted PDF, or the Markdown / Mermaid preview to a richly formatted PDF with headings, lists, tables, code blocks, and images as native vector text. You can also export a Markdown file’s preview to a standalone, self-contained .html file (embedded stylesheet, heading anchors, math as images) with Preview: Export to HTML, which opens the result in a new tab, or to MS Word (.docx) and OpenDocument Text (.odt) with Preview: Export to Word / OpenDocument. Headings, styling, lists, tables, code, math, Mermaid diagrams, and images all carry over. Or print either, with a page-by-page preview first (what you preview is what prints). Output is always light-themed and generated off the UI thread.

Commands: editor.exportPdf, preview.exportPdf, preview.exportHtml, preview.exportDocx, preview.exportOdt, editor.print, preview.print. Line numbers, syntax highlighting, and page size live in Settings → Editor → Export & Print.