The best way to minify HTML online is by b using the fixcode.org HTML minifier

Fixcode.org also has the following minifiers

  1. CSS minifier: https://fixcode.org/minify/css
  2. javaScript minifier:https://fixcode.org/minify/js
  3. JSON minifier: https://fixcode.org/minify/json
  4. XML minifier: https://fixcode.org/minify/xml