Package tidy

http://www.html-tidy.org/

When editing HTML it's easy to make mistakes. Wouldn't it be nice if
there was a simple way to fix these mistakes automatically and tidy up
sloppy editing into nicely laid out markup? Well now there is! Dave
Raggett's HTML TIDY is a free utility for doing just that. It also
works great on the atrociously hard to read markup generated by
specialized HTML editors and conversion tools, and can help you
identify where you need to pay further attention on making your pages
more accessible to people with disabilities.

Version: 5.8.0