Minify HTML, it can be harsh, so test the results.

HTML-minify-cleaner.js

function minhtm(r, R) {
  R = "replace";
  return r[R](/>(\n| |	)*</g, "><")[R](/[a-z-]+=""/g, "")[R](/"([^ ]*)"/g, "$1")[R](/<\/li>/, "");
}

var minifyHtml = function() {
  var r = /<(pre|style|script(?![^>]*?src))[^>]*>[\s\S]*?<\/\1>/gi, e = /("|')(?:\\\1|[^\1])*?\1/g, n = /__str(\d+)__/g, t = /<preserved>/g, c = /<!--(?!\s*?\[\s*?if)[\s\S]*?-->/gi, s = "", i = /(?:\s+=|=\s+)(?=[^<]*>)/g, p = "=", a = /\s*>/g, l = ">", u = /\s+(?=[^<]*>)/g, g = " ", o = />\s+</g, f = "><", _ = /(<\w+ )([^>]*)/g, v = function(r, e, n) {
    return e + n.split(" ").sort().join(" ");
  }, m = /<.*?class=("|')([^\1]*)\1/gi, h = function(r, e, n, R) {
    var t = n.split(/\s\s*/g).sort().join(" ");
    return r[R](n, t);
  };
  return function(d,R) {R = "replace";
    var y = [], j = [], S = function(r) {
      return y.push(r), "<preserved>";
    }, w = function() {
      return y.shift();
    }, H = function(r) {
      var e = j.length;
      return j[e] = r, "__str" + e + "__";
    }, z = function(r, e) {
      return j[+e];
    };
    return d[R](e, H)[R](r, S)[R](c, s)[R](i, p)[R](a, l)[R](u, g)[R](o, f)[R](_, v)[R](t, w)[R](n, z)[R](m, h).trim();
  };
}();

//usage: document.getElementById('outz').value=minhtm(minifyHtml(document.getElementById('inz').value));

Minified to 925 bytes:

function minhtm(r,R){R="replace";return r[R](/>(\n| |   )*</g,"><")[R](/[a-z-]+=""/g,"")[R](/"([^ ]*)"/g,"$1")[R](/<\/li>/,"")}var minifyHtml=function(){var r=/<(pre|style|script(?![^>]*?src))[^>]*>[\s\S]*?<\/\1>/gi,e=/("|')(?:\\\1|[^\1])*?\1/g,n=/__str(\d+)__/g,t=/<preserved>/g,c=/<!--(?!\s*?\[\s*?if)[\s\S]*?-->/gi,s="",i=/(?:\s+=|=\s+)(?=[^<]*>)/g,p="=",a=/\s*>/g,l=">",u=/\s+(?=[^<]*>)/g,g=" ",o=/>\s+</g,f="><",_=/(<\w+ )([^>]*)/g,v=function(r,e,n){return e+n.split(" ").sort().join(" ")},m=/<.*?class=("|')([^\1]*)\1/gi,h=function(r,e,n,R){var t=n.split(/\s\s*/g).sort().join(" ");return r[R](n,t)};return function(d,R){R="replace";var y=[],j=[],S=function(r){return y.push(r),"<preserved>"},w=function(){return y.shift()},H=function(r){var e=j.length;return j[e]=r,"__str"+e+"__"},z=function(r,e){return j[+e]};return d[R](e,H)[R](r,S)[R](c,s)[R](i,p)[R](a,l)[R](u,g)[R](o,f)[R](_,v)[R](t,w)[R](n,z)[R](m,h).trim()}}();