Looking for a reliable HTML minifier online? Paste any HTML document below and this free tool will strip comments, collapse redundant whitespace, and shrink your markup without breaking layout. Switch to Beautify mode to re-indent minified or tangled source into clean, readable code with a 2-space indent. Content inside pre, textarea, script, and style tags is preserved byte-for-byte so code samples and inline scripts remain intact. Everything runs locally in your browser — no upload, no sign-up, no tracking. See live byte-savings stats the moment you minify so you know exactly how much you shaved off.
Last updated: March 2026
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Frequently Asked Questions
What does an HTML minifier do?
An HTML minifier reduces the file size of an HTML document by removing unnecessary characters without changing how the page renders. Typical operations include stripping HTML comments, collapsing multiple whitespace characters into a single space, removing whitespace between adjacent tags, and trimming leading/trailing whitespace inside attribute values. The result is smaller payloads, faster network transfer, and lower bandwidth bills on high-traffic sites. A good minifier also leaves anything semantically meaningful — like the contents of <pre> or <script> blocks — completely untouched.
Is it safe to minify HTML automatically?
Generally yes, provided the minifier preserves the contents of whitespace-sensitive tags such as <pre>, <textarea>, <script>, and <style>. This tool leaves those blocks untouched. However, whitespace between inline elements can sometimes matter visually (for example, a space between two adjacent links), so always diff the minified output against the original in a browser before deploying to production. Conditional comments for legacy IE like <!--[if IE]> are also preserved.
How much smaller does minified HTML get?
Typical savings range from 10% to 40% depending on how much whitespace and commenting exists in the source. Hand-written templates with lots of indentation and developer comments compress more; generated markup that was already compact compresses less. Enabling gzip or Brotli on the server provides additional compression on top of minification — combined, you can often ship a page in 70–85% fewer bytes than the raw source. For a page above the LCP fold, those savings translate directly into faster perceived load.
Does minifying HTML improve SEO or Core Web Vitals?
Minification reduces transfer size, which improves Largest Contentful Paint (LCP) and Time to First Byte (TTFB), both ranking signals tracked in Google's Core Web Vitals report. Smaller HTML also parses faster on low-powered mobile devices, helping First Input Delay (FID) and the newer Interaction to Next Paint (INP) metric. The SEO impact is indirect but real: Google has stated that speed is a ranking factor, and the Chrome UX Report feeds real-user metrics back into Search Console.
Should I minify HTML in development or only in production?
Only minify production builds. During development, readable HTML is critical for debugging in DevTools, viewing source, and diffing in version control. Most modern static site generators and bundlers — including Next.js, Astro, Eleventy, and Gatsby — minify at build time automatically so you get readable dev output and compact production output without any manual step. Use this tool when you're working with a legacy pipeline or need to minify a one-off snippet.
What about inline CSS and JavaScript?
This tool preserves the contents of <script> and <style> blocks verbatim so your inline logic keeps working exactly as written. If you also want to minify those, run the extracted CSS through our CSS Minifier and the JavaScript through our JS Minifier, then paste the results back into your HTML. Splitting the concerns this way gives you safer, more predictable output than a single tool that tries to do everything at once.