There is tidy. I was going to say "but it's not kept up with standards", but find whilst researching this comment that it has been extended to HTML5.

https://www.w3.org/People/Raggett/tidy/

Search shows a few other options as well: https://duckduckgo.com/?q=html+linter&t=ftas&ia=web

Unless I'm misreading your question.