📝 Markdown Live Previewer
Write and preview GitHub-flavored markdown in real time. Features instant split-screen HTML rendering, code syntax styling, and one-click HTML copy.
Markdown Editor & HTML Live Preview
🚀 Free Markdown Live Editor
Welcome to OnlineToolHubs live markdown editor. Type markdown on the left to see the rendered HTML preview on the right in real time!
Features
Code Example
javascript
function greetUser(name) {
return Welcome to OnlineToolHubs, ${name}!;
}
> "Simplicity is the soul of efficiency." — Austin Freeman
| Tool Category | Available Tools | Status | | :--- | :--- | :--- | | Finance | Loan, Salary, Crypto, Margins | ✅ Live | | Developer | JSON, Base64, Diff, CSV | ✅ Live | | Health | BMI, TDEE, Calorie | ✅ Live |
What Markdown Live Previewer Does
Markdown is a plain-text formatting syntax that converts to HTML, designed by John Gruber in 2004 around one goal: the source should be readable as-is, without looking like markup. That is why emphasis is asterisks rather than tags, and why a list looks like a list before anything renders it.
The catch is that Gruber’s original description left a lot undefined, so implementations diverged. CommonMark exists to fix that — a strict specification with a test suite — and GitHub Flavored Markdown builds tables, task lists, strikethrough and autolinks on top of it. Most of what people mean by "Markdown" today is GFM.
This previewer covers the common syntax: headings, bold, italic, links, images, lists, blockquotes, inline code, fenced code blocks and horizontal rules. It is a lightweight converter rather than a CommonMark implementation, so deeply nested structures and the specification’s more obscure edge cases will not match a reference parser exactly.
Links are restricted to http, https, mailto and relative paths, and all text is escaped before rendering. That matters more than it sounds: a Markdown previewer that inserts link URLs into HTML unescaped will happily execute a javascript: URL or break out of the attribute entirely, which is a genuine hole and one this tool previously had.
How to Use Markdown Live Previewer
- Type or paste your Markdown syntax in the left editor
- Watch the formatted HTML preview update live in the right pane
- Use headers (#), bold (**), code blocks, and tables
- Click Copy Raw HTML when ready to use in your website or CMS
Formula Used by Markdown Live Previewer
The syntax this previewer handles
# Heading **bold** *italic* [text](url)  > quote - item 1. item `code` ```block``` ---
- Heading
- one to six hashes, matching h1 through h6
- list
- a hyphen, asterisk or number followed by a space
- blank line
- the paragraph separator — a single newline does not start a new paragraph
Worked example
The most common mistake: expecting a single newline to break a line.
- Markdown joins consecutive lines into one paragraph.
- A blank line starts a new paragraph.
- Two trailing spaces, or a backslash, force a line break within one.
Result: If your text is running together, the fix is almost always a blank line.
Syntax and what it produces
| Markdown | Result |
|---|---|
| `# Title` | Heading level 1 |
| `**text**` | Bold |
| `*text*` or `_text_` | Italic |
| `[label](https://example.com)` | Link |
| `` | Image |
| `> quoted` | Blockquote |
| `- item` | Bulleted list |
| `1. item` | Numbered list |
| `` `code` `` | Inline code |
| `---` | Horizontal rule |
Which flavor you are writing for
| Flavor | Adds |
|---|---|
| CommonMark | The strict base specification, with a conformance test suite |
| GitHub Flavored Markdown | Tables, task lists, strikethrough, autolinks, footnotes |
| Original Gruber Markdown | The 2004 description — ambiguous in places, which is why the others exist |
How to Read Your Result
Blank lines do the structural work
Almost every "why is my Markdown wrong" question comes down to a missing blank line — before a list, before a heading, or between paragraphs. Adding one fixes it more often than any other change.
Rendering differs by destination
GitHub, GitLab, Reddit, Discord and static site generators all support slightly different sets. Tables and task lists are GFM extensions, not universal, so check them where they will actually be published before assuming they work.
This is a preview, not a specification-compliant parser
The conversion here is regex-based and covers common syntax well. For anything where exact conformance matters — nested lists inside blockquotes, reference-style links, HTML mixed into Markdown — check the output in the system that will publish it.
Limitations & Accuracy Notes
- Not a CommonMark implementation. Deeply nested and unusual constructions will differ from a reference parser.
- GFM extensions such as tables, task lists and footnotes are not rendered.
- Raw HTML in the source is escaped rather than passed through, which is deliberate but differs from GitHub’s behavior.
- Link URLs are limited to http, https, mailto and relative paths; anything else is rendered as plain text rather than made clickable.
- Reference-style links and definition lists are not supported.
Frequently Asked Questions
What is Markdown?
Can I export the rendered HTML?
Which Markdown flavor does it render?
Is my document uploaded?
Why is my line break being ignored?
Can I use HTML inside Markdown?
Why is my nested list not indenting?
References & Further Reading
- CommonMark specification — The strict specification, with a conformance test suite, that most modern parsers target
- GitHub Flavored Markdown specification — The CommonMark superset that adds tables, task lists, strikethrough and autolinks
- Daring Fireball — Markdown syntax — Gruber’s original 2004 description