Free HTML Formatter Online
Format, indent, and clean up HTML code instantly. Fix improper nesting, add consistent indentation, and make your HTML readable.
HTML Formatter
HTML Formatter vs HTML Beautifier
Technically identical. Both add indentation and structure to HTML code without changing how it renders. The difference is purely in who uses each term: "formatter" is preferred by backend developers and engineers who are used to code formatters in other languages. "Beautifier" is more common among front-end developers, designers, and people learning HTML. This tool serves both audiences equally well.
Common HTML Formatting Issues
Missing closing tags
An unclosed div, li, or p tag causes unpredictable layout bugs across browsers.
Incorrect nesting
Block elements (div, p) inside inline elements (span, a) is invalid HTML and causes rendering inconsistencies.
Inconsistent indentation
Mixed tabs and spaces, or random indentation levels, make HTML impossible to read and debug.
Attributes on wrong lines
Many attributes crammed on one line become unreadable. A formatter breaks them onto separate lines when needed.
Missing DOCTYPE declaration
Without doctype, browsers enter quirks mode and render HTML differently across browsers.
HTML Formatting Rules and Best Practices
- •Always declare DOCTYPE at the top: <!DOCTYPE html>
- •Use lowercase tag names: <div> not <DIV>
- •Quote all attribute values: class="container" not class=container
- •Close all tags, including optional ones like </li> and </p>
- •Indent nested elements consistently (2 or 4 spaces throughout)
- •Place each block element on its own line
- •Add lang attribute to the <html> tag for accessibility
- •Add alt attribute to all <img> tags
Frequently Asked Questions
How do I format HTML code automatically?
Paste your HTML and click Beautify HTML. The formatter applies Prettier's HTML rules with your chosen indent size.
What does an HTML formatter do?
It adds consistent indentation, line breaks, and structure to HTML code without changing how the page renders.
How do I fix badly formatted HTML?
Paste the HTML and click Beautify. For structural issues, check the warnings panel which flags common HTML problems.
What is the correct way to indent HTML?
Nest each child element one indent level deeper than its parent. Block elements get their own lines. Choose 2 or 4 spaces and apply it consistently.
Can I format HTML in Notepad?
Standard Notepad cannot format HTML. Use this tool online, or install VS Code with the Prettier extension for local formatting.