Free Markdown to HTML Converter

How this tool computes its result

Both directions are implemented with sequential regex replacements, not a spec-compliant parser. `markdownToHtml` replaces headers, bold, italic, links, images, fenced code blocks, and inline code, converts list-item lines to `<li>`, then groups consecutive `<li>` runs into `<ul>` or `<ol>` (deciding ordered vs. unordered by checking whether the original markdown line for the first `<li>` text started with a digit), and wraps any remaining bare lines into `<p>` tags based on blank-line boundaries. `htmlToMarkdown` reverses each of those regexes independently (headers, strong/b, em/i, a, img, pre/code, code, li, blockquote, hr, p) and finally strips any tags that weren't matched by a specific rule.

Worked example

Input `# Title\n\n**Bold** and *italic*\n\n- one\n- two` converts to: ``` <h1>Title</h1> <p><strong>Bold</strong> and <em>italic</em></p> <ul><li>one</li> <li>two</li></ul> ```

When not to use this tool

This is not a CommonMark-compliant parser — nested structures (lists inside blockquotes, tables, nested emphasis, raw HTML passthrough) are not handled by any of the regex rules and will pass through as literal text or render incorrectly rather than throwing a clear error.

Common mistakes

• - Pasting HTML links or images with extra attributes (e.g. `<a href="x" target="_blank">`) — the link/image regexes expect a specific `href`/`src`+`alt` shape and will leave the tag unconverted in the Markdown output when attributes don't match.
• - Using tables or nested lists in the Markdown input — neither has a matching regex rule, so they get flattened into plain paragraph text in the HTML output instead of proper `<table>`/nested `<ul>` markup.
• - Repeatedly clicking Swap to round-trip content — since neither direction is a full parser, details like code-fence language hints or list nesting are lost on the first pass and cannot be recovered by converting back.

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