/markdown

Markdown Editor - Write and preview Markdown online

Write Markdown files with a live preview, format headers, links, tables, and download as .md or .html.

Markdown Editor

Write Markdown and preview the output in real-time.

Preview
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How it works

This Markdown editor runs completely locally in your browser. The content you type or files you open are never sent to a server, giving you 100% privacy and security.

What is Markdown?

Markdown is a lightweight markup language with plain-text formatting syntax (such as # for headings, * for italics, and ** for bold text). It makes it easy to write formatted text that can quickly be parsed into clean HTML.

About this tool

Markdown is a lightweight markup language designed so that raw text stays readable while it can be converted to nice HTML. The format was created by John Gruber in 2004 and has become the de facto standard for readme files on GitHub, documentation, static sites and most blog platforms. This tool lets you write Markdown on the left and see HTML plus a formatted preview live on the right. Common elements like headings, lists, tables, code blocks and links are supported, along with GitHub extensions like task checkboxes and strikethrough.

How to use it

  1. Write or paste Markdown into the left panel.
  2. See the formatted preview instantly on the right.
  3. Switch tabs to view raw HTML you can copy into your CMS.
  4. Use the toolbar shortcuts for bold, italic, links, images and code blocks if you prefer buttons.

Examples

Headings and bold
Input# Heading This is **bold** and *italic* text.
Output<h1>Heading</h1><p>This is <strong>bold</strong> and <em>italic</em> text.</p>
Links and images
Input[verktoy.dev](https://verktoy.dev) ![alt text](/logo.png)
Output<p><a href="https://verktoy.dev">verktoy.dev</a></p><p><img alt="alt text" src="/logo.png"></p>
Fenced code block
Input```js console.log("Hi") ```
Output<pre><code class="language-js">console.log("Hi") </code></pre>
Triple backticks followed by a language name give syntax colouring in most renderers.

Common use cases

  • Write READMEs, wikis and documentation that live in git.
  • Send formatted text into Slack, Discord, Teams and GitHub issues.
  • Publish blog posts in static site generators like Astro, Hugo, Jekyll.
  • Format notes in Obsidian, Notion, Bear or Standard Notes.
  • Convert Markdown to HTML before pasting into a CMS or newsletter.

Frequently asked questions

Which flavour of Markdown is supported?
CommonMark with a subset of GitHub Flavoured Markdown (GFM): tables, task checkboxes, strikethrough and fenced code blocks with language. Footnotes and raw HTML also work.
Is HTML content sanitised?
The preview is sanitised to prevent XSS, but the HTML output is returned as-is. Sanitise yourself before pasting into a production page.
Why doesn’t my image show up?
Images need an absolute URL or a relative path that works where the HTML is displayed. The tool cannot load local files from your machine. Use a data URL or upload the image somewhere first.
Can I convert HTML back to Markdown?
Not in this tool. Try Turndown or Pandoc for the reverse direction; the conversion is lossy because HTML allows more than Markdown.

Technical background

Markdown is typically parsed in two stages: first an abstract syntax tree (AST) is built from the source, then the AST is rendered to HTML. CommonMark is the standard spec (published 2014) and resolves many ambiguities in the original 2004 syntax. GitHub Flavoured Markdown adds tables, fenced code blocks with a language, task checkboxes (- [ ] text), autolinks and strikethrough (~~). MDX combines Markdown with JSX to embed React components in content. Security: Markdown allows raw HTML by default, so an inline <script> will run if the renderer does not sanitise. Popular parsers include marked, markdown-it, remark and cmark (the reference implementation). Performance: a typical 5,000-word article parses in under 10 ms with modern parsers.