JPKCom DB

Markdown Editor

What the JPKCom Markdown Editor does: live preview, GFM, KaTeX, Mermaid, and export — your starting point for the manual, examples, and tips.

Write Markdown and see the result instantly

The Markdown Editor is a full editor with live preview: you type Markdown on the left and watch the rendered result update in real time on the right. The two columns scroll in sync, so even in long documents you always keep the spot you're working on in view. There's nothing to save, nothing to compile, no build step — you write, and the preview follows.

This solves a real everyday problem: Markdown is easy to read, but small mistakes — a missing blank line before a list, a crooked table column, a code fence that never closes — only surface when the document renders. With live preview you see the mistake the moment you make it, not after the commit or the upload to your CMS.

The tool is built for everyone who writes Markdown regularly: developers maintaining READMEs, changelogs, or API docs; writers drafting blog posts or notes; and anyone who needs a cleanly formatted document fast, without opening a heavy office suite. Everything runs in the browser — no account, no installation.

What the editor can do — at a glance

  • Live preview with synchronized scrolling — editor and preview side by side, or editor only / preview only. The preview comes in three reading themes: Dark, Light, and Sepia.
  • GitHub Flavored Markdown and more — tables, strikethrough, task lists, and auto-linked URLs (GFM) plus a whole set of extensions: footnotes, definition lists, subscript/superscript, highlight, abbreviations, emoji shortcodes, KaTeX math, and Mermaid diagrams. Code blocks render with syntax highlighting.
  • A convenient toolbar — buttons for every formatting (headings, bold, italic, lists, tables, links, images, code), plus a table-of-contents panel, six document templates (README, Changelog, Blog Post, Meeting Notes, API Docs, MIT License), and find/replace.
  • A real code editor underneath — the ACE editor with line numbers, syntax highlighting, undo/redo, move lines, fullscreen, and configurable themes.
  • Automatic saving — your text is kept in your browser's localStorage and is back after a reload.
  • Import and export — open and save .md files, load Markdown from a URL, and copy the rendered result as HTML, save it as an HTML file, export it to PDF, or print it.

Exactly what each button does, which Markdown syntax is supported, and the keyboard shortcuts are all in the manual.

Runs in the browser — what goes to the server, and what doesn't

The editor works entirely in your browser. Your text is rendered, saved, and exported without anything being sent to a server — the auto-save lives in your own browser's localStorage, and the PDF and HTML exports are produced locally too.

There is exactly one feature that talks to the server at all: Load Markdown from URL. When you enter an address, an internal, token-protected proxy on the JPKCom server fetches the content of that URL and drops it into the editor. This is necessary because your browser isn't allowed to load foreign pages directly for security reasons (CORS). All that goes to the server is the URL you want to load — never the text you type yourself. Details and the limits of this proxy are in the manual.

Try it now

→ Open the Markdown Editor — type, watch the preview, done. No account, free, right in the browser. If you don't want to start from scratch, the Templates menu in the toolbar loads a ready-made skeleton for README, Changelog, Blog Post, and more.

  • WYSIWYG Editor — the closest relative: a rich-text HTML editor based on TipTap with Markdown import and export. If you'd rather work visually than in Markdown syntax, that's the alternative — and you can move content back and forth between the two tools.
  • Source Viewer — view source code for 100+ languages with syntax highlighting. Handy for inspecting the editor's HTML output.
  • Beautify — format JavaScript, CSS, and HTML; useful for tidying up exported HTML.
  • llms.txt Generator — Markdown is the natural format for AI context; use this tool to build a valid llms.txt for your content.

There's more on the subpages: the manual with every function, every button, and the full syntax range; hands-on examples; and a collection of tips & tricks.