Something like that:
var tagList = {};
var tag;
document.querySelectorAll('*').forEach(function(node) {
tag = node.tagName.toLowerCase();
if (!tagList[tag]) {
tagList[tag] = 1;
} else {
tagList[tag]++;
}
});
tagList; // object, where key - html tag, and value – tag count per html document
Enjoy!
solved How to get only all HTML tags to list from string using javascript or jquery? [closed]