HTML, CSS & JS Minifier and Beautifier – Free Online Code Optimizer

HTML, CSS & JS Minifier & Beautifier

Minify or beautify HTML, CSS & JavaScript with industry-grade engines (Terser, CSSO, js-beautify). Drag-drop files, batch ZIP, URL fetch, validation, savings stats, share & history — all client-side.

Input 0 chars · 0 lines · 0 B
Output 0 chars · 0 lines · 0 B
🗂 Batch mode — process multiple files & download as ZIP
History (last 10)
JS not loaded — if this stays visible, WordPress (wpautop/AIOS) is mangling the script. See notes.

How to Use the HTML / CSS / JS Minifier & Beautifier

  1. Choose your language tab — HTML, CSS, JavaScript, or let Auto-detect figure it out.
  2. Paste code, upload a file, drag & drop, fetch from a URL, or load a sample.
  3. Pick a mode: Minify, Beautify, Validate, or Stats.
  4. Toggle options — indent style, comment removal, mangle names, preserve licenses.
  5. Click Process (or enable Auto-run). View savings, copy, download, or share via link.
  6. Use Batch mode to minify dozens of files at once and download a single ZIP.

What is HTML / CSS / JS Minification?

Minification removes every byte that doesn't affect how code runs — whitespace, comments, long variable names, redundant rules. Result is typically 30–80% smaller, meaning faster downloads, less bandwidth, better Core Web Vitals, and higher SEO rankings.

Beautification does the opposite: expands minified code into readable form for debugging or learning.

This tool uses Terser (JS), CSSO (CSS), and a custom HTML minifier — all running 100% client-side.

Common Use Cases

🚀 Production deploymentShrink JS/CSS bundles before pushing to CDN.
📈 SEO & Core Web VitalsSmaller assets improve LCP and FID.
📧 Email HTMLStay under Gmail's 102 KB clip limit.
🔍 Debug minified codeBeautify third-party scripts to read them.
💾 Reduce bandwidth costsLower S3/CloudFront/Vercel egress bills.
🎓 Learn from production codePretty-print minified libraries.
🔐 Light obfuscationMangle JS names to hinder reverse-engineering.
📱 AMP & mobile pagesMeet AMP's 75 KB CSS budget.
🧹 Code clean-upStandardize indentation across a team.
📦 WordPress themes/pluginsOptimize assets without a build step.

Why Choose Our Minifier?

⚡ Industry-grade enginesTerser, CSSO & js-beautify.
🔒 100% privateRuns entirely client-side.
🎯 3-in-1 suiteHTML, CSS & JavaScript in one interface.
🔄 Two-wayMinify and beautify both directions.
📊 Live savings statsBytes, KB, percentage, gzipped estimate.
🗂 Batch ZIP modeProcess dozens of files at once.
🌐 URL fetchPull CSS/JS from any public URL.
🧠 Auto-detectSmart language detection.
📜 HistoryLast 10 processings saved locally.
🌙 Dark modeEasy on the eyes.
🖥 FullscreenDistraction-free editor.
🔗 Share linkRestore code & settings via URL.
⌨️ Keyboard shortcutsCtrl/⌘+Enter to process.
📏 Custom indent2/4 spaces or Tab.
💬 License preservationKeep /*!*/ headers.
🛠 Mangle & compressToggle JS name mangling.
📂 Drag & dropDrop files into input.
♾ Free & unlimitedNo signup, no caps.
✅ ValidationCatch syntax errors first.

Frequently Asked Questions

Is minification safe?

For valid code, yes — Terser/CSSO are battle-tested. Pitfalls: JS depending on function names at runtime (disable mangle), CSS depending on source order (disable restructure).

How much smaller will my files get?

HTML 20–40%, CSS 30–50%, JS 40–80%. With gzip on top, total transfer often drops 80%+.

What's the difference between minification and obfuscation?

Minification keeps code readable; obfuscation actively hinders reverse-engineering.

Can I minify SCSS, LESS, or TypeScript?

Compile to plain CSS/JS first, then minify here.

Is my code uploaded?

No — everything runs in your browser.

ES2023+ supported?

Yes — Terser supports all latest ECMAScript features.

Can I unminify third-party scripts?

Yes, use Beautify mode.

What's the file size limit?

~10 MB single, ~50 MB batch.

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