Terser JS Minifier is a powerful online tool designed to optimize JavaScript code. It reduces file size by removing unnecessary whitespace, comments, and shortening variable names without breaking functionality. Smaller files mean faster download speeds and quicker page loads, which are crucial for better user experience and SEO rankings.

Legacy compressors often crash when processing modern JavaScript features. Terser is built specifically to handle ES6+ syntax, including arrow functions, classes, and async/await. This ensures your modern code is minified correctly and efficiently, making it the industry standard for contemporary web development.

Mangling renames your long variable and function names into short letters (like transforming 'userAccount' into 'a'). This significantly reduces the code size beyond simple compression. You should generally keep this enabled for production builds to get the smallest possible file size and basic code obfuscation.

Yes, security is a priority. This tool runs entirely in your web browser. Your code is processed locally on your device and is never uploaded to or stored on any server, ensuring your intellectual property and sensitive logic remain completely private.