HTML Formatter: Format and Minify HTML Markup

Pretty-print or minify HTML documents and fragments in this browser. Parsing uses DOMParser as text/html, so the result is the HTML DOM — not an XML round-trip. Script, style, textarea, and pre content stays intact. Markup is never executed and is written to the output as text only.

Format options Indent Input scope Void elements Strip HTML comments

HTML input Load file

Drop a .html or .txt file here. Client-only FileReader. Nothing is uploaded.

Formatted output

Output is assigned as plain text. User HTML is never inserted as live DOM nodes.

Paste HTML and press Pretty-print or Minify. Work stays in this browser.

HTML is not XML — what this tool does

The HTML Living Standard parser always builds a document tree. It lowercases HTML tag names, implies missing html/head/body tags, auto-closes elements, moves some tags, and ignores end tags on void elements. This formatter serializes that tree. It is a pretty-printer and minifier, not a validator and not an XML canonicalizer.

Void elements (area, base, br, col, embed, hr, img, input, link, meta, param, source, track, wbr) are written without a closing tag.
Script, style, textarea, title, and pre content is preserved. Inline JavaScript is not executed.
SVG and MathML are HTML foreign content after the HTML parser — not a true XML round-trip. Namespace prefixes and XML self-closing rules are only approximated.
There is no live preview iframe. Output is text in a textarea so scripts, images, and event handlers cannot run on this page.