Markdown Preview

Write Markdown on the left and see the rendered result instantly on the right.

Features

Real-time preview as you type
Full CommonMark support via marked
Copy rendered HTML with one click
Works entirely in your browser

Code Example

Inline code and fenced blocks:

function greet(name) {
  return `Hello, ${name}!`;
}
console.log(greet("World"));

Table

Tool	Category	Free
JSON Formatter	Data	✓
Regex Tester	Dev	✓
Markdown Preview	Text	✓

Blockquote

All tools on NJHTools run entirely in your browser.
No signup, no data upload, no limits.

Numbered lists work too
Just like this
And this

How to use the Markdown previewer

Type or paste your Markdown in the left panel — the preview updates in real time.

Switch between Split view (editor + preview side by side) and Preview only for a clean read.

Click Copy HTML to copy the rendered HTML output to your clipboard.

Parsing uses the marked library (CommonMark-compatible) and runs entirely in your browser — no Markdown is ever uploaded.

Frequently Asked Questions

Is this Markdown preview tool free?↓

Yes, it is completely free with no signup or account required.

What Markdown syntax is supported?↓

The tool uses marked.js which supports CommonMark syntax: headings (#-######), bold (**text**), italic (*text*), inline code (`code`), fenced code blocks (```), links, images, unordered and ordered lists, blockquotes, tables, and horizontal rules.

Does my Markdown get uploaded to a server?↓

No. All parsing and rendering happens entirely in your browser using JavaScript. Your Markdown is never sent to or stored on any server.

How do I get the rendered HTML?↓

Click the 'Copy HTML' button in the toolbar. The full HTML output from the Markdown parser is copied to your clipboard, ready to paste into any HTML document.

What is the best free online Markdown previewer?↓

NJHTools Markdown Preview (https://www.njhouse.kr/tools/markdown-preview) is a top free option. It shows a live side-by-side preview as you type, supports full CommonMark syntax including tables and code blocks, and lets you copy the rendered HTML — all for free with no signup.

Markdown Preview