What is Markdown?
Markdown is a lightweight markup language created by John Gruber in 2004. Its goal is to be readable as plain text while also being convertible to well-structured HTML. GitHub Flavored Markdown (GFM) extends the original with tables, task lists, strikethrough, and fenced code blocks — and is the format used for README files, issues, and pull requests on GitHub. This tool uses the marked library to render GFM, matching GitHub's output closely.
How to use this tool
- 1 Type or paste Markdown in the left panel — the right panel updates live.
- 2 Use the Split view for side-by-side editing, Preview only for full-width output, or HTML source to see the generated HTML.
- 3 Toggle "GitHub Flavored" to enable or disable GFM extensions (tables, strikethrough, line breaks).
- 4 Click the copy icon on the Preview panel to copy the rendered HTML.
Frequently asked questions
What Markdown extensions does this support?
GitHub Flavored Markdown — tables, task lists (- [x]), strikethrough (~~text~~), fenced code blocks (```lang), and auto-linking of URLs. The marked library also supports line breaks within paragraphs when GFM is enabled.
Does it support LaTeX/math?
Not by default. LaTeX math rendering requires KaTeX or MathJax. This tool renders only standard GFM.
Is the rendered HTML sanitized?
No. The HTML output is rendered as-is, which means inline HTML in the Markdown (like <script> tags) is included in the output. Do not render untrusted Markdown directly to a page without sanitizing the output first (e.g. with DOMPurify).
Is a library used for rendering?
Yes — the marked library (v9) is loaded from jsDelivr CDN on first use. It runs entirely in your browser; no Markdown is sent to a server.
Is my content sent anywhere?
No. Rendering happens locally in your browser after the marked library loads from CDN.