Every Good web designer uses CSS minifier tool to compress the wholw code instantly. Since the CSS file load from the client site, so it is very helpful to increase the website speed if you upload the minified version of CSS file. Yes, it a good habit of professional web designer. But if you want to edit the file again you need to use any tool to unminify or Beautify CSS code.
This Unminifier tool must help you to beautify any compressed HTML code correctly. So, convert your HTML to a friendly readable format to make it easier to read by creating proper indentation. If you are a professional web designer you may know that a good HTML formatter or beautify tool will keep spaces, tabs between content tags such as div and span as it is considered to be valid content. This website will help you to get your desired result appropriately.