Markdown Preview

What is Markdown Preview?

A Markdown preview renders Markdown syntax into HTML in real time, letting you see exactly how headers, lists, links, bold text, italic text, blockquotes, and code blocks will appear before publishing. Markdown is the standard lightweight markup language for README files, technical documentation, blog posts, GitHub issues, and static site generators like Hugo, Jekyll, and Next.js MDX. Writers focus on content structure without wrestling with HTML tag nesting.

Markdown uses plain-text conventions that convert to HTML: hash prefixes for headings (# H1, ## H2), asterisks for emphasis (*italic*, **bold**), backticks for inline code, triple backticks for code blocks, hyphens or asterisks for unordered lists, and numbers for ordered lists. Links use bracket-parenthesis syntax text. These conventions are readable in source form and render to semantic HTML that search engines and screen readers can parse.

Our preview tool parses your Markdown in the browser and renders sanitized HTML output alongside the source editor. DOMPurify strips dangerous tags and attributes — script injections, event handlers, and javascript: URLs — preventing cross-site scripting (XSS) attacks even if you paste untrusted Markdown from external sources. This sanitization is critical when previewing user-generated content or third-party documentation.

All rendering happens locally. Draft blog posts, internal documentation, proprietary README content, and pre-release announcement text never upload to external servers. Copy the rendered HTML for CMS paste, export for email templates, or use the preview to verify formatting before pushing to GitHub or your documentation platform.

Markdown documents often include JSON code blocks, XML examples, and SQL snippets. Format embedded JSON with the JSON Formatter, structure XML with the XML Formatter, and compare documentation revisions with the Diff Checker. For placeholder content in drafts, use the Lorem Ipsum Generator.

Technical writers, open-source maintainers, developer advocates, bloggers, and product managers use Markdown preview when drafting README files, writing API documentation, preparing blog posts for static site generators, composing GitHub issue and PR descriptions, and reviewing contributor documentation before merge.

When should you use Markdown Preview?

Preview README.md drafts before pushing to GitHub to verify heading hierarchy, link formatting, and code block rendering.

Draft blog posts and technical articles in Markdown and verify HTML output before publishing to your CMS or static site.

Compose GitHub issue descriptions, pull request bodies, and discussion posts with confidence in final formatting.

Test Markdown syntax for documentation sites, wikis, and knowledge bases without running a local dev server.

How to Use Markdown Preview

1. Write or paste Markdown in the input editor.
2. Click Preview to render HTML.
3. View sanitized HTML output side by side.
4. Use for README drafts, docs, and blog posts.

Features

• Live Markdown to HTML rendering in the browser
• Support for headers, lists, links, bold, italic, blockquotes, and code blocks
• HTML output sanitized with DOMPurify to prevent XSS attacks
• Side-by-side source and preview layout
• Standard Markdown syntax compatible with most platforms
• 100% client-side rendering — content never sent to servers
• Instant preview with no account or build step required
• Copy rendered HTML for paste into CMS or email tools

Example

The hash prefix creates an H1 heading. Double asterisks render as strong (bold) text. Hyphen-prefixed lines become an unordered list with anchor links. The triple-backtick fenced code block preserves JSON syntax highlighting structure in a pre/code element. This is standard Markdown that GitHub, GitLab, and most static site generators render identically.

# Format Hubs Guide

A **free** browser-based formatting toolkit.

- [JSON Formatter](/json-formatter)
- [XML Formatter](/xml-formatter)

```json
{"status": "ok"}
```

<h1>Format Hubs Guide</h1>
<p>A <strong>free</strong> browser-based formatting toolkit.</p>
<ul>
<li><a href="/json-formatter">JSON Formatter</a></li>
<li><a href="/xml-formatter">XML Formatter</a></li>
</ul>
<pre><code>{"status": "ok"}</code></pre>

Common Errors

Best Practices

• Preview README and documentation drafts here before committing to version control
• Use language-tagged code fences for JSON, JavaScript, SQL, and shell examples
• Keep heading hierarchy sequential (H1 → H2 → H3) for accessibility and SEO
• Write alt text in image syntax  for screen reader accessibility
• Compare documentation revisions with the Diff Checker before publishing updates
• Trust the sanitizer — do not disable XSS protection when rendering user-generated Markdown
• Use relative links like [JSON Formatter](/json-formatter) for internal documentation
• Test link URLs in preview before publishing to catch broken references

Frequently Asked Questions