Practical guide
How to use the js minifier
The JavaScript minifier removes unnecessary formatting and applies safe reductions to make source smaller for delivery. It is best used on tested source in a build workflow, with an original copy and source maps retained for debugging.
Good reasons to use it
- Compare the size of an uncompressed script with a minified version.
- Prepare a small standalone script for production delivery.
- Inspect whether whitespace and comments account for avoidable transfer size.
A reliable workflow
- Paste non-secret JavaScript and keep a backup of the source.
- Generate the compact output and review any reported issue.
- Run automated and browser tests before deploying the result.
How to interpret the result
A smaller file can improve transfer cost, but HTTP compression, caching and code splitting also matter. Minification does not remove unused code unless the processor explicitly performs tree-shaking.
Frequently asked questions
Is minification the same as compression?
No. Minification changes source text; gzip or Brotli compresses bytes during transfer. Production sites often use both.
Will minification make code secure?
No. It may make casual reading harder, but browser-delivered code remains accessible and should not contain secrets.