Formatters

HTML Formatter/Validator

Format, validate, and minify HTML code online free

HTML Input

Indent type

Indent size

Self-closing

Quotes

Wrap length

About

Formats and minifies HTML with configurable indentation, self-closing tag style, quote style, and attribute sorting. Removes comments and empty attributes, formats embedded CSS and JavaScript within style/script tags, and detects tag mismatches to highlight unclosed or mis-nested elements.

HTML generated by templates or server-side rendering is often minified or poorly indented, making it difficult to debug or review. This formatter beautifies the markup while also catching structural issues like tag mismatches that cause rendering bugs.

Who should use this tool?

Web developers debugging rendered HTML output, code reviewers auditing template-generated markup, and QA engineers checking for proper HTML structure.

Common use cases

Beautify compressed HTML output from a production server for debugging rendering issues
Sort attributes alphabetically to enforce a consistent code style across a team
Remove HTML comments before deploying to production to reduce page weight
Check for tag mismatch errors in complex nested templates before pushing to production
Format embedded CSS in <style> blocks and JavaScript in <script> blocks simultaneously

How to Use

Paste or type the HTML you want to format or minify in the input area

Set the indent size (2 or 4 spaces, or tabs) and choose self-closing tag style (trailing / or not)

Select quote style: single or double quotes for attribute values

Toggle options: sort attributes alphabetically, remove comments, remove empty attributes

Enable format embedded CSS/JS to also beautify content inside <style> and <script> tags

Click Format to see the output; tag mismatch warnings appear highlighted in the output area

Examples

Input: '<div><p>hello</p></div>' with 2-space indent. Output: formatted with each tag on its own line, properly indented by 2 spaces.

Input: '<div><p>hello</div></p>' (mismatched). Output: formatted HTML plus a highlighted error pointing out the closing tag mismatch.

Best Practices

Run format before code reviews to catch structural issues that are invisible in minified HTML
Enable 'remove comments' only for production assets, not during development
Use attribute sorting to enforce a consistent order (e.g., class, id, data-* before other attrs)
Check embedded CSS/JS formatting with the option enabled to ensure consistent code style

Common Mistakes

Assuming the formatter fixes HTML errors; it detects mismatches but does not auto-correct them
Using remove comments during development, losing important context for debugging
Applying a tab width inconsistent with the rest of the project's code style
Not checking the embedded CSS/JS formatting option and wondering why scripts remain unformatted

FAQ

Does the formatter fix invalid HTML? No, it detects and reports tag mismatches but does not auto-correct them.

Can I format only a selection of the HTML? The tool formats the entire document; use an editor plugin for partial formatting.

What happens to inline event handlers like onclick? They are preserved and not modified by formatting.

Does it preserve conditional comments for IE? Yes, conditional comments are preserved during formatting.

Related Tools

Same Category — Formatters

JSON Formatter

Format, validate, and minify JSON data with syntax highlighting

SQL Formatter

Format and beautify SQL queries with syntax validation

JavaScript Minifier/Beautifier

Minify, beautify, and validate JavaScript code with customizable options

CSS Formatter/Minifier

Format, beautify, and minify CSS code online free

Popular Tools

Base64 Encoder/Decoder

Encode and decode Base64 strings online free

JWT Decoder

Decode and analyze JWT tokens online free

URL Encoder/Decoder

Encode and decode URLs and URL components online free

Learning Resources

Dive deeper with our comprehensive guides and tutorials.

HTML Formatter/Validator - Beginner's Guide

5 min read

HTML Formatter/Validator Advanced Techniques

8 min read

About

Who should use this tool?

Web developers debugging rendered HTML output, code reviewers auditing template-generated markup, and QA engineers checking for proper HTML structure.

Common use cases

Beautify compressed HTML output from a production server for debugging rendering issues
Sort attributes alphabetically to enforce a consistent code style across a team
Remove HTML comments before deploying to production to reduce page weight
Check for tag mismatch errors in complex nested templates before pushing to production
Format embedded CSS in <style> blocks and JavaScript in <script> blocks simultaneously

How to Use

Paste or type the HTML you want to format or minify in the input area

Set the indent size (2 or 4 spaces, or tabs) and choose self-closing tag style (trailing / or not)

Select quote style: single or double quotes for attribute values

Toggle options: sort attributes alphabetically, remove comments, remove empty attributes

Enable format embedded CSS/JS to also beautify content inside <style> and <script> tags

Click Format to see the output; tag mismatch warnings appear highlighted in the output area

Best Practices

Run format before code reviews to catch structural issues that are invisible in minified HTML

Enable 'remove comments' only for production assets, not during development

Use attribute sorting to enforce a consistent order (e.g., class, id, data-* before other attrs)

Check embedded CSS/JS formatting with the option enabled to ensure consistent code style

Common Mistakes

Assuming the formatter fixes HTML errors; it detects mismatches but does not auto-correct them

Using remove comments during development, losing important context for debugging

Applying a tab width inconsistent with the rest of the project's code style

Not checking the embedded CSS/JS formatting option and wondering why scripts remain unformatted

FAQ

Does the formatter fix invalid HTML? No, it detects and reports tag mismatches but does not auto-correct them.

Can I format only a selection of the HTML? The tool formats the entire document; use an editor plugin for partial formatting.

What happens to inline event handlers like onclick? They are preserved and not modified by formatting.

Does it preserve conditional comments for IE? Yes, conditional comments are preserved during formatting.

HTML Formatter/Validator

About

Who should use this tool?

Common use cases

How to Use

Examples

Best Practices

Common Mistakes

FAQ

Related Tools

Same Category — Formatters

JSON Formatter

SQL Formatter

JavaScript Minifier/Beautifier

CSS Formatter/Minifier

Popular Tools

Base64 Encoder/Decoder

JWT Decoder

URL Encoder/Decoder

Learning Resources

Share

HTML Formatter/Validator

About

Who should use this tool?

Common use cases

How to Use

Examples

Best Practices

Common Mistakes

FAQ

Related Tools

Same Category — Formatters

JSON Formatter

SQL Formatter

JavaScript Minifier/Beautifier

CSS Formatter/Minifier

Popular Tools

Base64 Encoder/Decoder

JWT Decoder

URL Encoder/Decoder

Learning Resources

Share