Markdown to HTML

This turns Markdown into HTML, converting headings, emphasis, inline code, links, bullet lists, blockquotes and paragraphs into their tag equivalents. Text that contains HTML special characters is escaped first, so a snippet of markup written inside a Markdown document appears literally instead of being interpreted.

That escaping step is the detail that makes the output trustworthy. Explaining markup in a document requires showing the markup rather than executing it, and a converter that passes raw angle brackets through would turn a tutorial into a page of unintended elements.

It handles the core syntax rather than every extension in circulation. Tables, footnotes, task lists and fenced code blocks with syntax highlighting are not part of the subset it recognises, so content relying on them should be checked after conversion.

Because the conversion runs as a sequence of pattern substitutions rather than through a real parser, the limits show up in the details. A fenced code block is not treated as a unit — the fence line itself is discarded and the lines inside it are processed as ordinary prose, so any asterisk or underscore within a code sample is read as emphasis and turned into a tag. Setext headings underlined with dashes or equals signs are not recognised, ordered lists are not given their own handling, and a blockquote spanning several paragraphs is not kept together. Nothing here reports what it did not understand, so a document that leans on extensions should be read through before it is published rather than trusted on sight.