Skip to content
File Compressors

JS Minifier

Minify JavaScript files.

  • Free
  • No sign-up
  • Files stay on your device

or drop a file here

paste with Ctrl/⌘+V · Accepted: .js, .mjs

Files stay on your device — nothing is uploaded

More compressors

What does JS Minifier do?

JS Minifier makes JS files smaller without uploading them anywhere. Spaces, line breaks and comments are removed. The code works exactly the same.

Typically 10–40% smaller before your server’s gzip, which adds further savings.

What you can use

One or more JS files — drag them onto the box or tap to choose.

How to use JS Minifier

  1. Step 1

    Drop your file(s) on the upload box or tap to choose.

  2. Step 2

    Start compression — no settings needed.

  3. Step 3

    Compare the before and after sizes, then download the result (or all files at once).

Good to know

  • This is lossless: the content is untouched, only the packing changes.
  • Keep your readable source and minify only the copy you publish.
  • If a file can’t be made smaller, the tool tells you and keeps the original instead of making it worse.

Your privacy

Your file is opened and processed by your own browser — it is never uploaded. That also means big files use your device’s memory, so very large files can be slow on older phones.

Related tools

All File Compressors
PNG CompressorShrink PNGs while keeping transparency and sharp edges.JPG CompressorShrink photos for email and uploads — pick a quality and preview.JPEG CompressorOptimise JPEG photos for the web at the quality you choose.WebP CompressorMake WebP images even smaller for faster pages.GIF CompressorReduce the size of animated GIFs.SVG CompressorMinify SVG code — remove metadata, comments and spaces.

Frequently asked questions

Is JS Minifier free?

Yes. JS Minifier is completely free, with no sign-up, no watermark and no daily limit.

Are my files uploaded to compress them?

No. Compression runs inside your browser, on your device. Nothing is uploaded, which is why it is safe for private photos and documents — and why big videos depend on your device’s speed.

How much smaller will my file get?

It depends on the file. Phone photos often shrink 50–80%, WAV audio 80–90% and image-heavy PDFs about half. Light aims for about 20% smaller, Medium about 35% and Heavy about 50%. Files that are already compressed (MP3s, ZIPs of JPGs) change little — if the result isn’t smaller, you get your original back.

Does it work on my phone?

Yes. It works in Chrome, Safari and other modern browsers on Android and iPhone — pick files from your gallery or Files app. Large videos and long PDFs are faster on a computer.