Markdown to HTML Converter
Convert Markdown to clean HTML with a live preview, or paste HTML and get Markdown back. Supports headings, lists, tables, code blocks, links, images and blockquotes. Everything runs in your browser, and your content never leaves your device. No upload, no sign-up, no tracking.
- Live preview
- GitHub flavored tables
- Two way conversion
- Works offline
Output updates live. Nothing is sent to a server.
- Runs in your browser
- No upload
- No sign-up
- No tracking
- Two way converter
- Works offline
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Markdown to HTML
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How this compares to other Markdown converters
Most online Markdown tools send your text to a server and often render it with third party scripts. This one converts locally in your browser.
| Feature | TToolDeck | Desktop editors | Typical online tools |
|---|---|---|---|
| Runs entirely in your browser | Yes | No | No |
| Markdown never sent to a server | Yes | No | No |
| No sign-up or account | Yes | No | No |
| Live preview while you type | Yes | Partial | Yes |
| GitHub flavored tables | Yes | Yes | Yes |
| Fenced code blocks with language | Yes | Yes | Yes |
| Reverse HTML to Markdown | Yes | No | Partial |
| Free without paywalls | Yes | Yes | Partial |
| Works offline after page loads | Yes | No | No |
Comparison reflects publicly available information at the time of writing. Features may change.
How it works
- 1
Pick a direction
Choose Markdown to HTML or HTML to Markdown. The editor and preview adjust to the direction you picked.
- 2
Paste your content
Drop your Markdown or HTML in the left pane. The right pane updates live as you type. No button to press.
- 3
Copy or download
Copy the result to your clipboard or save it as a .html or .md file. Nothing is sent to a server at any step.
Everything you get for free
Two way converter
Convert Markdown to HTML, or paste HTML and get clean Markdown back. One tool for both directions.
Headings and paragraphs
Every ATX heading level (# to ######) and paragraph is emitted as the correct HTML element. Setext headings are supported too.
Bold, italic, strikethrough
Double asterisks and double underscores for bold, single for italic, and double tilde for strikethrough. All nest correctly.
Links and images
Inline links and images with title attributes. The output uses standard anchor and img tags that work in any browser or CMS.
Fenced code blocks
Triple backticks with an optional language tag. HTML entities inside the block are escaped so the code renders literally.
GitHub flavored tables
Pipe tables with a header separator row become proper thead and tbody elements. Cell alignment markers are recognised.
Lists and blockquotes
Unordered and ordered lists nest properly. Blockquotes collapse multi-line quotes into a single blockquote block.
Nothing leaves your device
There is no backend. The parser is a pure JavaScript function that runs in your tab. Your text, links and code stay on your computer.
What people use it for
Blog and CMS content
Draft posts in Markdown and convert them to HTML for WordPress, Ghost, Ghostty or any custom CMS that takes raw HTML.
README and docs
Turn a Markdown README into HTML for a documentation site, or into Markdown if the source was already HTML.
Emails in a rich editor
Write in Markdown, convert to HTML and paste into an email editor that accepts formatted content.
Notion or Obsidian export
Move content out of Markdown based apps into any HTML based platform without retyping the formatting.
Static site generators
Preview how a Markdown source will look once Hugo, Jekyll or Nextra turns it into HTML before you commit.
Learning Markdown
Paste Markdown and see the HTML it produces, side by side, to learn the syntax by example.
Questions people ask
Is my Markdown sent to a server?
No. The converter runs entirely in JavaScript on your device. Your text, links, code samples and any embedded content never leave your browser. Turn off wifi after the page loads and it still works.
What Markdown syntax is supported?
ATX headings (# through ######), paragraphs, bold, italic, strikethrough, inline code, fenced code blocks with optional language, links, images, unordered and ordered lists, blockquotes, horizontal rules, and GitHub flavored pipe tables.
Does it support GitHub flavored Markdown?
The most common GFM features are supported: fenced code blocks with language tags, pipe tables with alignment, strikethrough with double tildes, and task list syntax is rendered as text. Task list checkboxes are not converted to input elements.
Can I convert HTML back to Markdown?
Yes. Switch the mode toggle to HTML to Markdown. Headings, paragraphs, bold, italic, links, images, lists, blockquotes, code blocks and simple tables are all converted back.
Does the preview use my styles?
No. The preview uses ToolDeck styles so you can see the rendered structure. The HTML output itself has no classes or inline styles, so you can drop it into any site and style it with your own CSS.
Does it sanitize the HTML?
In Markdown to HTML mode, any HTML tags inside the Markdown source are escaped before processing, so a script tag in the Markdown becomes visible text, not executable code. In HTML to Markdown mode, the input is parsed with the browser DOM parser and converted to text, so no scripts run.
What about footnotes and definition lists?
Footnotes and definition lists are not supported. The syntax renders as plain paragraphs. For full CommonMark and extension support, use a dedicated library like markdown-it or remark.
Can I paste HTML with inline styles?
Yes, but inline styles are dropped during conversion. Only semantic tags (headings, paragraphs, bold, italic, links, images, lists, tables, code) are preserved. This keeps the resulting Markdown clean and portable.
Does it handle nested lists?
Yes. Nested unordered and ordered lists are parsed and emitted with proper nesting. Indentation of two spaces per level is the convention the parser follows.
Does the output include a full HTML document?
By default you get the HTML fragment only, which is what you want for pasting into a CMS, an email, or a template. If you want a full document with head and body, wrap the fragment yourself or click the Wrap in full HTML checkbox.
Is there a size limit?
No hard limit. Documents up to a few hundred KB convert instantly. Very large Markdown files with thousands of lines may take a second on a slow device.
Can I use this for commercial work?
Yes. There are no restrictions on the output. Whatever rights you hold over the source, you keep over the converted result. Businesses use this for docs, blogs, email and internal wikis.
Does it support CommonMark strict mode?
The parser aims for CommonMark compatibility on the core syntax. Strict edge cases (HTML blocks with nested comments, link reference definitions with unusual escapes) may not be handled exactly. For strict compliance, use a reference implementation.
Is the output valid HTML5?
Yes. Headings, paragraphs, lists, tables and code blocks all use standard HTML5 elements. The output passes HTML5 validation for well-formed input Markdown.
Can I download the result?
Yes. The Copy button sends the output to your clipboard. The Download button saves it as a .html file in Markdown mode, or as a .md file in HTML to Markdown mode.
Your content never leaves your device
There is no upload step and no server-side handling. The converter is a pure JavaScript function that runs in your browser tab. Your Markdown, HTML, code samples and any embedded links stay on your computer. Open the browser network tab while using the tool and confirm there are no outbound requests carrying your content. Read how we keep it private.