HTML Formatter & Beautifier

Paste raw or minified HTML and instantly get clean, indented, syntax-highlighted output. Validates structure and flags common errors like unclosed tags and missing quotes.

Indent: 2 spaces 4 spaces Tabs

Paste your HTML above and click Format HTML to see the result.

About the HTML Formatter

This free online HTML formatter (also called an HTML beautifier or HTML pretty printer) takes raw, minified, or poorly indented HTML and reformats it with consistent indentation and line breaks, making it easy to read, debug, and maintain. It also validates common structural issues and reports them with clear descriptions.

What is HTML?

HTML (HyperText Markup Language) is the standard markup language for web pages. Browsers parse HTML to render content, and well-formed, consistently indented HTML is essential for maintainability, accessibility, and collaboration.

Features

Syntax highlighting for tags, attributes, values, comments, and doctypes
Choose between 2-space, 4-space, or tab indentation
Minify HTML to a single compact line
Inline validation — flags unclosed tags, missing attributes, and structural warnings
Correctly handles void elements (<br>, <img>, <input>, <meta>, etc.)
Preserves <script>, <style>, and <pre> content without re-indenting
Copy to clipboard or download as an .html file
100% client-side — your data never leaves your browser

How to use

Paste your HTML into the input box (or click Sample to load an example).
Select your preferred indentation style.
Click Format HTML to beautify, or Minify to compact.
Any warnings or errors appear above the output panel.
Copy the result to your clipboard or download it as a file.

Common HTML issues

Unclosed tags — tags like <div>, <p>, and <span> require a matching closing tag.
Missing alt on images — <img> elements should always include an alt attribute for accessibility.
Missing doctype — documents should begin with <!DOCTYPE html> to trigger standards mode.
Unquoted attributes — attribute values should always be wrapped in double quotes.
Deprecated elements — tags like <center>, <font>, and <marquee> are obsolete in HTML5.