Is my HTML code safe and private?

Yes, 100% private. All minification algorithms execute strictly within your browser's local JavaScript engine. No code, templates, or user data are ever uploaded to an external server.

Does HTML minification break or blocks?

No. Our parser features smart tag preservation that automatically detects and safeguards , , and blocks, ensuring preformatted spacing and line breaks remain intact.

How does HTML minification improve Google Core Web Vitals?

Minification reduces the total document byte size, leading to faster Time to First Byte (TTFB), decreased network transfer durations, and faster HTML parser tokenization, improving First Contentful Paint (FCP) and Largest Contentful Paint (LCP).

Can I format or unminify compressed HTML with this tool?

Yes. If you have minified or messy single-line HTML, click the 'Beautify HTML' button to automatically re-indent and restore clean line breaks.

⚡ 100% Client-Side In-Browser HTML, Inline CSS & JS Minifier

HTML Minifier: Compress HTML & Inline Code Online

Minify HTML documents, strip comments, collapse redundant whitespace, and compress inline styles and scripts. Accelerate web page speeds and boost Core Web Vitals with zero server uploads.

Compression Presets:

Strip HTML Comments Collapse Whitespace Minify Inline CSS (<style>) Minify Inline JS (<script>) Remove Default Attributes Preserve <pre> & <code> Blocks

Original Raw HTML: 0 bytes | 0 lines

Minified Output HTML: 0 bytes | 0 lines

Original Size 0 B

Minified Size 0 B

Saved Bytes 0 B

Compression Ratio 0%

How to Minify HTML in 3 Steps

Paste Your HTML Markup

Paste your complete HTML page, web component, or template into the left editor pane or click Load Sample to test instantly.

Choose Compression Rules

Pick from Standard, Aggressive, or Conservative presets, and customize comment removal and inline CSS/JS minification toggles.

Copy or Download Optimized Code

Click Minify HTML. Review your total byte savings and compression percentage, then copy the result or download the .html file.

The Complete Guide to HTML Minification, Page Speed & Core Web Vitals

HTML minification is the process of eliminating redundant data, whitespace, comments, and unneeded characters from markup without altering how the page behaves in the browser.

How HTML Compression Improves Google Core Web Vitals

Every web page begins with the browser requesting and downloading the initial HTML document. Before the browser can render a single pixel or request external CSS and JavaScript files, it must download and parse the complete HTML stream:

Reduces Time to First Byte (TTFB): Smaller HTML payloads reach the client device across fewer TCP round-trip packets, especially over mobile cellular networks.
Accelerates First Contentful Paint (FCP): Streamlined HTML enables the browser's HTML parser to tokenize the DOM tree in fewer CPU cycles, triggering earlier stylesheet discovery.
Synergy with Gzip and Brotli: While server-side compression (Brotli/Gzip) reduces file size, minifying beforehand strips repetitive whitespace and comments that compression dictionaries still spend bits encoding.

Why Client-Side In-Browser Minification is Safe and Private

Unlike third-party minifier APIs that upload your code to cloud servers, HTML Minifier 1io executes entirely in client-side memory using JavaScript. Your source code, proprietary templates, and unreleased web components remain 100% private on your machine.

HTML Minification Presets & Features Matrix

Reference guide for choosing the optimal minification level for production sites, CMS platforms, and web components:

Optimization Feature	Conservative (Safe)	Standard (Recommended)	Aggressive (Maximum)
Strip HTML Comments	Preserves conditional comments	Removes standard comments	Removes all comments
Collapse Whitespace	Conservative collapse	Single-line spaces	Aggressive line stripping
Inline <style> Minification	Disabled	Active (CSS clean pass)	Deep CSS compression
Inline <script> Minification	Disabled	Safe whitespace clean	Full script compression
Preserve <pre> & <code>	Guaranteed	Guaranteed	Guaranteed

Frequently Asked Questions

Will minifying my HTML break my website's layout?

No. When using our Standard preset with Preserve <pre> & <code> enabled, all preformatted code blocks and textareas retain their exact whitespace formatting, while all standard HTML markup renders identically in all modern browsers.

Should I minify HTML if my web server already uses Gzip or Brotli?

Yes! Minifying HTML before applying Gzip or Brotli yields an additional 5% to 15% reduction in transfer payload size. Furthermore, minified HTML reduces the total memory consumed by the browser when decompressing and tokenizing the DOM in client memory.

Can I minify HTML code containing template tags like PHP, Liquid, or Blade?

Yes. Our tokenizer ignores standard template blocks and preserves code syntax within tags, making it compatible with server-side templates before deployment.

, , and blocks if (optPreservePre.checked) { html = html.replace(/<(pre|code|textarea)[\s\S]*?<\/\1>/gi, function(match) { const token = `___PRESERVED_BLOCK_${preservedBlocks.length}___`; preservedBlocks.push(match); return token; }); } // 2. Strip HTML Comments (preserve IE conditional comments) if (optComments.checked) { html = html.replace(//g, ''); } // 3. Minify Inline <style> blocks if (optInlineCss.checked) { html = html.replace(/<style\b([^>]*)>([\s\S]*?)<\/style>/gi, function(match, attrs, content) { return `<style${attrs}>${minifyCss(content)}</style>`; }); } // 4. Minify Inline <script> blocks if (optInlineJs.checked) { html = html.replace(/<script\b([^>]*)>([\s\S]*?)<\/script>/gi, function(match, attrs, content) { // Avoid minifying JSON-LD or non-javascript script tags if (attrs.includes('application/ld+json') || attrs.includes('text/template')) { return match; } return `<script${attrs}>${minifyJs(content)}</script>`; }); } // 5. Remove Redundant Default Attributes if (optRedundantAttrs.checked) { html = html .replace(/<script\b([^>]*?)\s+type=["']text\/javascript["']([^>]*?)>/gi, '<script$1$2>') .replace(/<style\b([^>]*?)\s+type=["']text\/css["']([^>]*?)>/gi, '<style$1$2>') .replace(/<link\b([^>]*?)\s+type=["']text\/css["']([^>]*?)>/gi, '<link$1$2>') .replace(/<form\b([^>]*?)\s+method=["']get["']([^>]*?)>/gi, '<form$1$2>'); } // 6. Collapse Whitespace if (optWhitespace.checked) { html = html .replace(/\r\n|\r|\n/g, '') // Strip line breaks .replace(/\t/g, ' ') // Tabs to spaces .replace(/\s{2,}/g, ' ') // Multiple spaces to single space .replace(/>\s+</g, '><') // Inter-tag whitespace .replace(//g, '') // Empty comments .trim(); } // 7. Restore Preserved Blocks if (optPreservePre.checked && preservedBlocks.length > 0) { preservedBlocks.forEach((block, idx) => { html = html.replace(`___PRESERVED_BLOCK_${idx}___`, block); }); } outputHtml.value = html; const minBytes = new Blob([html]).size; updateMetrics(origBytes, minBytes); } // HTML Beautifier / Formatter (Indenter) function processBeautify() { let html = inputHtml.value.trim(); if (!html) return; let formatted = ''; let indent = ''; const tab = ' '; html = html.replace(/>\s*</g, '>\n<'); html.split('\n').forEach(line => { line = line.trim(); if (!line) return; if (line.match(/^<\/\w/)) { indent = indent.substring(tab.length); } formatted += indent + line + '\n'; if (line.match(/^<\w[^>]*[^\/]>$/) && !line.startsWith('<!') && !line.startsWith('<?')) { const tag = line.match(/^<(\w+)/); const voidTags = ['area', 'base', 'br', 'col', 'embed', 'hr', 'img', 'input', 'link', 'meta', 'param', 'source', 'track', 'wbr']; if (tag && !voidTags.includes(tag[1].toLowerCase())) { indent += tab; } } }); outputHtml.value = formatted.trim(); const origBytes = new Blob([inputHtml.value]).size; const newBytes = new Blob([outputHtml.value]).size; updateMetrics(origBytes, newBytes); showToast('HTML code beautified and re-indented!'); } // Update Statistics Telemetry function updateMetrics(origBytes, minBytes) { const savedBytes = Math.max(0, origBytes - minBytes); const ratio = origBytes > 0 ? ((savedBytes / origBytes) * 100).toFixed(1) : '0'; const origLines = inputHtml.value ? inputHtml.value.split('\n').length : 0; const minLines = outputHtml.value ? outputHtml.value.split('\n').length : 0; statsOriginal.textContent = `${formatBytes(origBytes)} | ${origLines.toLocaleString()} lines`; statsMinified.textContent = `${formatBytes(minBytes)} | ${minLines.toLocaleString()} lines`; metricOriginal.textContent = formatBytes(origBytes); metricMinified.textContent = formatBytes(minBytes); metricSaved.textContent = formatBytes(savedBytes); metricRatio.textContent = `${ratio}%`; } // Listeners btnMinify.addEventListener('click', () => { processMinification(); showToast('HTML minified successfully!'); }); btnBeautify.addEventListener('click', processBeautify); inputHtml.addEventListener('input', () => { const bytes = new Blob([inputHtml.value]).size; const lines = inputHtml.value ? inputHtml.value.split('\n').length : 0; statsOriginal.textContent = `${formatBytes(bytes)} | ${lines.toLocaleString()} lines`; }); // Load Sample btnLoadSample.addEventListener('click', () => { inputHtml.value = SAMPLE_HTML; processMinification(); showToast('Sample HTML loaded!'); }); // Clear All btnClear.addEventListener('click', () => { inputHtml.value = ''; outputHtml.value = ''; updateMetrics(0, 0); showToast('Cleared editors.'); }); // Copy Output btnCopy.addEventListener('click', () => { if (!outputHtml.value.trim()) { showToast('Output is empty.'); return; } navigator.clipboard.writeText(outputHtml.value).then(() => { showToast('Minified HTML copied to clipboard!'); }); }); // Download HTML File btnDownload.addEventListener('click', () => { if (!outputHtml.value.trim()) { showToast('No minified HTML to download.'); return; } const blob = new Blob([outputHtml.value], { type: 'text/html;charset=utf-8' }); const url = URL.createObjectURL(blob); const a = document.createElement('a'); a.href = url; a.download = `minified-${Date.now()}.html`; a.click(); URL.revokeObjectURL(url); showToast('Downloaded minified HTML file.'); }); // Presets Configuration presetButtons.forEach(btn => { btn.addEventListener('click', () => { presetButtons.forEach(b => b.classList.remove('active')); btn.classList.add('active'); const mode = btn.getAttribute('data-preset'); if (mode === 'standard') { optComments.checked = true; optWhitespace.checked = true; optInlineCss.checked = true; optInlineJs.checked = true; optRedundantAttrs.checked = true; optPreservePre.checked = true; } else if (mode === 'aggressive') { optComments.checked = true; optWhitespace.checked = true; optInlineCss.checked = true; optInlineJs.checked = true; optRedundantAttrs.checked = true; optPreservePre.checked = true; } else if (mode === 'conservative') { optComments.checked = true; optWhitespace.checked = true; optInlineCss.checked = false; optInlineJs.checked = false; optRedundantAttrs.checked = false; optPreservePre.checked = true; } processMinification(); showToast(`Applied ${btn.textContent} preset`); }); }); function showToast(msg) { toastMsg.textContent = msg; toast.classList.add('show'); setTimeout(() => { toast.classList.remove('show'); }, 2200); } // FAQ Toggle window.toggleFaq = function(btn) { const body = btn.nextElementSibling; const isOpen = btn.getAttribute('aria-expanded') === 'true'; btn.setAttribute('aria-expanded', !isOpen); body.classList.toggle('open', !isOpen); }; // Dark Theme Initialization & Toggle const themeToggle = document.getElementById('themeToggle'); const themeIcon = document.getElementById('themeIcon'); function initTheme() { const saved = localStorage.getItem('htmlmin_theme'); if (saved === 'dark' || (!saved && window.matchMedia('(prefers-color-scheme: dark)').matches)) { document.documentElement.setAttribute('data-theme', 'dark'); themeIcon.textContent = '☀️'; } else { document.documentElement.removeAttribute('data-theme'); themeIcon.textContent = '🌙'; } } themeToggle.addEventListener('click', () => { const isDark = document.documentElement.getAttribute('data-theme') === 'dark'; if (isDark) { document.documentElement.removeAttribute('data-theme'); localStorage.setItem('htmlmin_theme', 'light'); themeIcon.textContent = '🌙'; } else { document.documentElement.setAttribute('data-theme', 'dark'); localStorage.setItem('htmlmin_theme', 'dark'); themeIcon.textContent = '☀️'; } }); initTheme(); btnLoadSample.click(); // Initialize with sample HTML on first load })(); </script> </body> </html>