HTML, CSS and JavaScript minifier.

How much difference does minifying make?

Minifying often saves 10 to 30 percent of a file's size before compression. But your server should also be compressing files with gzip or Brotli, and that often has a much bigger effect. Run the page size checker to see whether compression is on and which files are heaviest. On most sites, images are the bigger win, so try the image compressor too.

What this minifier does and doesn't do

• HTML: removes comments and extra whitespace, and minifies inline scripts and styles. It leaves pre and textarea alone, and conditional comments stay.
• CSS: removes comments and spaces that do nothing, and keeps spaces inside calc() that are needed.
• JavaScript: removes comments and needless spaces. It keeps a line break wherever removing one could change what the code means.
• It doesn't rename variables or remove unused code. For the smallest possible JavaScript, use a build tool such as Terser or esbuild.
• Comments starting with /*! are kept, since they're often licence notices.

On WordPress?

You rarely need to do this by hand, because a good caching plugin can minify files automatically. Whatever you use, keep your original files, since minified code is hard to edit. To make minified HTML readable again, use the HTML formatter.