The JavaScript Minifier is a free online tool that removes unnecessary characters from JavaScript code — including whitespace, comments, line breaks and long variable names — to reduce file size and improve page load performance. Minified JS files can be 30–70% smaller than the originals, leading to significantly faster script loading.

JavaScript files are often the heaviest resource on a modern webpage. Reducing their size directly improves Time to Interactive (TTI) and Total Blocking Time (TBT) — two Core Web Vitals metrics that affect both user experience and Google rankings.

How to Minify JavaScript

• Paste your JavaScript code into the input field
• Click Minify JS
• Copy the minified output — it is functionally identical to the original but smaller
• Replace your original JS file with the minified version in production

What Gets Removed

• Single-line (//) and multi-line (/* */) comments
• Whitespace, line breaks and indentation
• Unnecessary semicolons
• Long variable/function names (in advanced mode)

Always keep your original source code in version control — only deploy the minified version. For CSS and HTML compression, see our CSS Minifier and HTML Compressor tools. Free, no login, instant results.

Want to learn more? Read our complete guide: How to Speed Up Your Website and Improve Core Web Vitals →