About This Tool
Markdown Preview uses an established local parser supporting common formatting and tables. This page focuses on the rendered reading experience; use the adjacent Markdown → HTML tool when you need source code.
How to Use It
- Enter Markdown or load the example with headings, lists, links, and tables.
- Pause briefly to see the live preview. Fenced code remains code text.
- Raw HTML is displayed literally, and images become text placeholders without automatic remote requests.
- Copy the original Markdown or download an MD file to keep editing.
Examples
- # Heading creates a level-one heading; **Bold** and *Italic* add emphasis.
- > quote, numbered lists, and fenced code blocks use their corresponding semantic structures.
- <script>alert(1)</script> is displayed as text without running a script.
Rules and Limits
Uses a local Markdown parser with raw HTML disabled. Unsafe URL schemes cannot create executable links, and code blocks are escaped. Images use text placeholders to prevent external resource requests. Preview updates after about 150 ms of inactivity; oversized inputs produce a limit message. Input limits: 200 KiB and 5,000 lines. Parsing and preview are limited to 20,000 tokens and 20,000 DOM nodes respectively; HTML output is limited to 1 MiB.
Common Uses
- Draft README files, technical notes, and documentation.
- Check heading levels, lists, block quotes, and tables.
- Safely inspect Markdown from other sources.
Privacy
Text processing, file reading, conversion, and previews all run locally in this browser. Input is not uploaded or automatically saved. No backend, database, online API, or third-party CDN is used. Copying and downloading also happen locally.
FAQ
What is Markdown?
It uses text markers such as #, *, and backticks for headings, emphasis, lists, and code. A parser can turn these structures into HTML.
Can the preview execute JavaScript?
No. Raw HTML is disabled and escaped, code blocks display code only, and unsafe link schemes are blocked.
Why are images missing?
To avoid automatically requesting remote resources, images appear as text placeholders rather than loading their original URLs.
Are tables supported?
Yes. Common Markdown tables with headers and separator rows are supported. Pipes inside cells must be escaped.
What does Copy copy?
This page copies the original Markdown input. Use Markdown → HTML for HTML source.