Markdown Previewer
Free Markdown previewer. Write Markdown and see a live, safely-rendered HTML preview — headings, lists, links, code, tables and more.
Hello, Markdown!
Write on the left, see the preview on the right.
Features
- Headings, bold, italic,
strikethrough inline codeand code blocks- Links and lists
Blockquotes look like this.
- First item
- Second item
const greet = () => "hi";Markdown lets you write formatted text in plain characters — asterisks for emphasis, hashes for headings — and it has become the default for README files, documentation, static site content, notes apps and chat platforms.
This previewer renders your Markdown live as you type, so you can check the output before committing or publishing. The renderer escapes all HTML, so no markup in your input can execute.
How to use the Markdown Previewer
Type or paste Markdown
The preview appears alongside and updates on every keystroke.
Check the rendered output
Headings, lists, links, code blocks, tables and blockquotes all render as they would on a site or in a README.
Fix and copy
Adjust until the output is right, then copy your source.
Markdown syntax reference
| Element | Syntax | Result |
|---|---|---|
| Heading 1 | # Title | Largest heading |
| Heading 2 | ## Section | Section heading |
| Bold | **text** | text |
| Italic | *text* | *text* |
| Strikethrough | ~~text~~ | Crossed out |
| Inline code | code | Monospaced |
| Link | [label](https://url) | Clickable link |
| Image |  | Embedded image |
| Bullet list | - item | Unordered list |
| Numbered list | 1. item | Ordered list |
| Blockquote | > quoted | Indented quote |
| Horizontal rule | --- | Divider line |
| Code block | Three backticks around lines | Preformatted block |
Mistakes that trip people up
- Blank lines matter. A heading or list immediately after a paragraph, with no blank line between, often fails to render.
- Trailing spaces make line breaks. Two spaces at the end of a line create a
<br>; a single newline usually does not break the line at all. - Nested lists need consistent indentation — two or four spaces, applied the same way throughout. Mixing them produces unpredictable nesting.
- Underscores inside words can trigger italics in some parsers.
snake_case_namemay render oddly; use backticks around identifiers. - Tables require a separator row of dashes under the header, or the whole block renders as plain text.
Flavours of Markdown
Markdown was created by John Gruber in 2004 with a deliberately loose specification, so implementations diverged. CommonMark is the standardised core that most modern parsers follow.
GitHub Flavored Markdown extends CommonMark with tables, strikethrough, task lists, automatic link detection and syntax-highlighted code fences. It is what you get in READMEs, issues and pull requests, and what most people mean by "Markdown" today.
Other platforms differ in the details — Slack, Discord, Notion and Reddit each support a partial and slightly different subset. Preview before publishing anywhere that matters.
Why Markdown became the default
- It is readable as plain text, so the source is usable even unrendered.
- It diffs cleanly in version control, unlike binary document formats where a one-word change produces an opaque diff.
- It is portable. The same file renders in GitHub, a static site generator, a notes app and a documentation platform.
- It is fast to write, with no reaching for a mouse to apply formatting.
- It converts easily to HTML, PDF and DOCX through tools like Pandoc.
A note on safety
Standard Markdown permits raw HTML, which means a Markdown document from an untrusted source can carry a script tag. Renderers that pass HTML through are a genuine cross-site-scripting risk.
This previewer escapes all HTML before rendering, so nothing in your input can execute. If you are building your own renderer, either disable raw HTML or sanitise the output with a library such as DOMPurify.
Frequently asked questions
What is Markdown?
A lightweight syntax for formatting plain text — **bold**, # heading, - list — that converts to HTML. It is the standard for README files, documentation and many notes and chat apps.
Does this support GitHub Flavored Markdown?
It supports the widely used core: headings, emphasis, lists, links, images, blockquotes, code blocks, tables and horizontal rules. Task lists and some GitHub-specific extensions are not rendered.
Why is my line break not showing?
A single newline does not create a line break in Markdown. End the line with two spaces, or leave a blank line to start a new paragraph.
Can I use HTML inside Markdown?
Many renderers allow it, but this previewer escapes all HTML for safety, so tags display as literal text rather than rendering.
How do I write a code block?
Wrap the lines in three backticks. Adding a language name after the opening fence enables syntax highlighting on platforms that support it.
Is my text uploaded?
No. Rendering happens entirely in your browser as you type, so unpublished drafts and internal documentation are safe.
How do I make a table?
Separate cells with pipes and put a row of dashes under the header. Without that separator row the whole block renders as plain text.
Can I export the rendered HTML?
The preview shows the rendered result; copy it from the preview pane to paste formatted content elsewhere. For file conversion, Pandoc handles Markdown to HTML, PDF and DOCX.
100% private. Files are processed on your device and never uploaded.
Instant results. No upload queue. Processing time depends on your device.
Free forever. No signup, no watermark, no paid tier.
Works everywhere. Use a modern browser on your phone or computer.
Related tools
Markdown Previewer is one of all the free tools on ToolNest. No account or subscription needed — anywhere in the world.