Overview
Some documents outlive their software. Word-processor files from the nineties are already archaeology; plain text from the seventies still opens. Markdown bets on the durable side: human-readable marks like # and * that any tool, in any decade, can turn into a proper document. READMEs, documentation, notes and static sites all speak it, and a live preview is the fastest way to learn it.
This previewer renders the widely-shared Markdown core as you type — headings, bold and italic, lists, links, images, inline code and fenced blocks, blockquotes, tables and horizontal rules — in a side-by-side view. When the document looks right, take the generated HTML for your CMS or download the .md source to keep.
Why write in Markdown at all?
Because it separates writing from formatting without hiding either. A word processor buries structure in binary; raw HTML buries writing in tags. Markdown keeps both visible: *this* plainly means emphasis, # plainly means a heading, and the source remains legible in any editor — which is why developers, writers and note-takers converged on it independently.
The catch is dialects. Core syntax works everywhere, but tables, footnotes and task lists vary between flavours. This previewer implements the common core plus GitHub-style tables and fenced code blocks, and states its support plainly so you always know what will render and what will not.
Features
- Live side-by-side preview re-rendered on every keystroke.
- Core-plus support: headings, emphasis, lists, links, images, code, quotes, tables, rules.
- Fenced code blocks with contents HTML-escaped so they cannot break the page.
- GitHub-style tables with header rows and alignment separators.
- Copy HTML for CMSs and emails; download .md to keep the portable source.
- Safe by construction: raw HTML in the source is escaped, never executed.
Benefits
- Learn by doing. Type a mark, see the result — faster than any cheat sheet.
- Draft without heavy editors. READMEs and docs in a single tab.
- Portable source. The .md file works on GitHub, in notes apps and in static generators.
- Private: your writing never leaves the browser.
Who can use it
Developers writing READMEs and documentation, writers drafting posts for static sites, students keeping publishable notes, support teams writing help articles, and anyone curious what the Markdown fuss is about. If you have ever fought a word processor over heading styles, this is the calmer alternative.
How to use
- Type or paste Markdown in the left pane — a sample document is preloaded to explore.
- Watch the formatted preview update live on the right.
- Copy the HTML when you need rendered output for a CMS or email.
- Download the .md file to keep your portable source.
- Press Clear to start a fresh document.
Frequently asked questions
Will this render the same on GitHub?
For the shared core — headings, emphasis, lists, links, code and quotes — essentially yes, and tables match GitHub's style too. Where flavours diverge is the exotic end: footnotes, task lists, definition lists and math. Those are not supported here, so verify them in their own previewers before publishing anything that depends on them.
Why is my raw HTML shown as text instead of rendered?
Deliberately, as a security measure. Executing arbitrary HTML typed into a previewer would be a textbook cross-site scripting hole, so the page escapes raw HTML and displays it as text instead. For trusted publishing pipelines where HTML must run, use a full Markdown processor with sanitisation rather than a live previewer.
Where did my single line breaks go?
Standard Markdown treats one line break as a space; paragraphs are separated by blank lines. End a line with two spaces for a hard break, or leave a blank line for a new paragraph. The previewer follows the standard rule, which is also why pasted text sometimes needs blank lines added.
How do I write a table?
Three parts: a header row in pipes, a separator row of dashes (| --- | --- |), then your data rows. Colons in the separator control alignment — | :--- | left-aligns, | ---: | right-aligns, | :---: | centres. Keep every row at the same column count and the table renders cleanly.
Is my document uploaded anywhere?
No. Rendering happens entirely in your browser; the text lives in the tab until you copy the HTML or download the file. There is no server round-trip at any point, so drafts and notes stay completely private. Drafts, notes and documentation stay completely private by architecture, not by promise.
Conclusion
Write it plain, preview it live, keep the .md file. Unlike proprietary formats, Markdown source will still open decades from now — the document and its future-proofing are the same thing.