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HTML Formatter & Minifier

Format HTML for readability or minify it for production.

  • 完全無料
  • 登録不要
  • ブラウザ上で安全に動作
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ガイド・解説

What HTML formatting and minifying do

This tool has two modes. Formatting (beautifying) takes messy or single-line HTML and adds consistent indentation and line breaks, so the nesting of elements is clear and the markup is easy to read and edit. Minifying does the reverse: it strips whitespace, line breaks, and optional comments to produce the smallest file for production. Neither changes how the page renders in a browser.

When to format vs. minify

Use formatted HTML while you are developing, reviewing, or debugging, because readable markup makes structure and mistakes obvious. Use minified HTML when you deploy, because smaller files download and parse faster. Most build tools minify automatically, but a manual formatter is invaluable for cleaning up exported markup, email templates, or HTML you have inherited from somewhere else.

Void elements and whitespace-sensitive tags

Correct HTML handling means respecting two special cases. Void elements such as br, img, input, hr, and meta never have closing tags, so the formatter does not try to add them. Whitespace-sensitive elements like pre, textarea, script, and style must keep their contents exactly as written, because reformatting them would change what the user sees or break the code inside. This tool preserves those blocks intact.

Does minifying break anything?

Properly minified HTML renders identically to the original. The risks come from naive whitespace collapsing inside sensitive elements, which this tool avoids, and from removing comments that are actually meaningful, such as Internet Explorer conditional comments. The minify options let you keep conditional comments and choose what to strip, so you get the size savings without surprises.

最終更新日: 2026年9月

Frequently Asked Questions

このツールは無料で安全に使えますか?
はい、完全無料でご利用いただけます。ブラウザ内でローカル処理されるため、機密情報も安全です。