HTML フォーマッター オンライン無料版

Free 無料 · ログイン不要 · データ保存なし
Indent
Error
HTML INPUT
OUTPUT
// formatted HTML output

その他の開発ツール

CSS フォーマッター
整形・圧縮
SQL フォーマッター
SQL 整形
HTML→Markdown
Markdown に変換
XML フォーマッター
整形・検証
正規表現
リアルタイムテスト
URL エンコード
パーセント変換
JSON フォーマッター
整形・検証・圧縮
Base64
エンコード

なぜこれが最高のオンラインHTMLフォーマッターなのか

フォーマット & 整形 HTML

Paste minified or poorly indented HTML and get back cleanly structured code with consistent indentation. Supports 2-space, 4-space, and tab indentation. Void elements like <br>, <img>, and <input> are handled correctly.

シンタックスハイライト

Color-coded tag names, attributes, values, comments, and doctype declarations make formatted HTML easy to review. The output panel renders the highlighted code without executing it.

HTMLの圧縮

Strip all formatting whitespace and HTML comments to produce compact, production-ready HTML. Reduces file size and speeds up page load time without changing how the page renders.

プライバシー最優先

All processing runs entirely in your browser — no HTML is ever sent to a server. Safe for templates containing sensitive data, internal admin pages, or proprietary front-end code.

よくある質問

What is an HTML formatter?

An HTML formatter (also called a beautifier or pretty printer) takes raw or minified HTML and reformats it with consistent indentation and line breaks, making the code easier to read and debug. It does not change how the HTML renders in a browser.

Does formatting HTML change how it looks in the browser?

No. HTML formatters only add or remove whitespace between tags. Browsers collapse multiple whitespace characters in most contexts, so formatting changes are invisible to end users. The only exception is content inside pre or textarea elements, where whitespace is significant.

What is HTML minification?

HTML minification removes unnecessary whitespace and comments to reduce file size. Minified HTML loads faster because smaller files transfer more quickly over the network. It is commonly applied to production HTML by build tools like webpack or Vite.

Why is my HTML indentation inconsistent?

Inconsistent HTML indentation is usually caused by mixing spaces and tabs, copying from different editors, or manual editing errors. Pasting your HTML into this formatter and applying a consistent indent style fixes all indentation at once.

詳細ガイド
開発者必須ツールガイド
正規表現・Cron・タイムスタンプ・URL
ガイドを読む
`; function lS(){document.getElementById('ia').value=SMP;onI();} async function pasteIn(){try{const t=await navigator.clipboard.readText();document.getElementById('ia').value=t;onI();}catch(e){}} async function cpO(ev){if(!oD)return;if(await cpT(oD)){const b=ev.currentTarget;b.style.color='var(--a)';setTimeout(()=>b.style.color='',900);}} function dlF(fn){if(!oD)return;const a=document.createElement('a');a.href=URL.createObjectURL(new Blob([oD],{type:'text/html'}));a.download=fn;a.click();} document.addEventListener('keydown',e=>{if((e.ctrlKey||e.metaKey)&&e.key==='Enter'){e.preventDefault();fmt();}});