HTML Prettify & Minify - Format HTML Online Free

Paste any HTML — even single-line minified output from a build pipeline — and the tool reformats it with proper indentation, one tag per line and consistent whitespace. Choose 2, 4 or 8-space indent. The output is ready to drop into your editor or paste into a code review comment.

Prettify expands HTML for readability: each tag on its own line, nested children indented, blank lines preserved between sections. Minify strips comments, collapses runs of whitespace and removes line breaks so the file ships in fewer bytes. Use prettify for editing and review, minify for production deployment.

No — js-beautify (the engine under the hood) detects script and style blocks and formats their contents with the appropriate JS or CSS rules, so inline scripts stay valid and stylesheets stay readable. Self-closing tags, void elements, and namespaced attributes (svg:xmlns, xlink:href) are all handled correctly.

It handles plain HTML and HTML-like templates well, but pure JSX (curly-brace expressions, fragments, capitalised component tags) is parsed as HTML and may pick up minor cosmetic issues. For framework-specific code we recommend Prettier configured for your dialect; for raw HTML, .htm, and template files our tool is perfect.

No upload happens. The formatter runs entirely in your browser with js-beautify, so you can safely paste internal page templates, draft emails, or HTML containing private data without anything leaving your device.

Minify strips HTML comments, collapses any run of whitespace between tags to a single space, and removes line breaks. The result is byte-identical-rendering HTML that is typically 10-30% smaller. Combined with gzip on the server, this shrinks initial page weight noticeably on content-heavy pages.

Yes — click Download to save the prettified output as output.html or the minified output as output.min.html. The file is UTF-8 encoded, so it works equally well with English, Cyrillic, CJK and right-to-left content.

It is a small browser-only utility — zero hosting cost — so we ship it free as part of our developer toolkit. No ads, no tracking on the output, no limits on file size beyond what your browser can hold in memory.

Prettify mode lets you pick 2, 4 or 8 spaces of indentation. Pick the width your editor or code style uses, then copy the result or download it as output.html so the formatting carries straight into your project.

The indent selector (2, 4 or 8 spaces) only applies in Prettify mode, since Minify strips all whitespace and line breaks by design — there is nothing left to indent. Switch back to Prettify to see the indent width take effect again.

As you paste or edit, the tool automatically runs a structural check and lists any unclosed, mismatched or stray closing tags directly under the output panel — no separate button needed. A green "No structural issues found" message confirms the markup is well-formed.

Use Prettify mode with 2-space indent — it's the most common convention and keeps diffs compact — then check the structural-issues panel to confirm they haven't left an unclosed tag. Once reviewed, switch to Minify mode before shipping to production to strip the extra whitespace back out.

Yes — drag an .html, .htm or .xhtml file onto the upload area, or click it to browse, and its contents load straight into the input box exactly as if you'd pasted them. From there, Prettify, Minify, indent width and the structural checker all work identically whether the markup came from a file or a paste.

Yes — once there's output, a Copy button appears next to the output panel and the primary action area. Clicking it copies the current Prettify or Minify result to your clipboard instantly (it briefly shows 'Copied!' for confirmation), so you can paste directly into your editor or a code review comment without saving an intermediate .html file.