HTML 5 introduced the <template> element which can be used for this purpose (as now described in the WhatWG spec and MDN docs).

A <template> element is used to declare fragments of HTML that can be utilized in scripts. The element is represented in the DOM as a HTMLTemplateElement which has a .content property of DocumentFragment type, to provide access to the template's contents. This means that you can convert an HTML string to DOM elements by setting the innerHTML of a <template> element, then reaching into the template's .content property.

Examples:

/**
 * @param {String} HTML representing a single node (which might be an Element,
                   a text node, or a comment).
 * @return {Node}
 */
function htmlToNode(html) {
    const template = document.createElement('template');
    template.innerHTML = html;
    const nNodes = template.content.childNodes.length;
    if (nNodes !== 1) {
        throw new Error(
            `html parameter must represent a single node; got ${nNodes}. ` +
            'Note that leading or trailing spaces around an element in your ' +
            'HTML, like " <img/> ", get parsed as text nodes neighbouring ' +
            'the element; call .trim() on your input to avoid this.'
        );
    }
    return template.content.firstChild;
}

const td = htmlToNode('<td>foo</td>'),
      div = htmlToNode('<div><span>nested</span> <span>stuff</span></div>');

/**
 * @param {String} HTML representing any number of sibling nodes
 * @return {NodeList} 
 */
function htmlToNodes(html) {
    const template = document.createElement('template');
    template.innerHTML = html;
    return template.content.childNodes;
}

const rows = htmlToNodes('<tr><td>foo</td></tr><tr><td>bar</td></tr>');

Note that similar approaches that use a different container element such as a div don't quite work. HTML has restrictions on what element types are allowed to exist inside which other element types; for instance, you can't put a td as a direct child of a div. This causes these elements to vanish if you try to set the innerHTML of a div to contain them. Since <template>s have no such restrictions on their content, this shortcoming doesn't apply when using a template.

Using <template>s was previously not always possible due to Internet Explorer not supporting <template>s, but IE support is almost never a consideration nowadays and Can I Use characterises <template>s as "baseline" functionality "widely available across major browsers". Except in the rare few cases where you find yourself writing web content for dead browsers, this approach will now reliably work for you.

Use insertAdjacentHTML(). It works with all current browsers, even with IE11.

var mylist = document.getElementById('mylist');
mylist.insertAdjacentHTML('beforeend', '<li>third</li>');

<ul id="mylist">
 <li>first</li>
 <li>second</li>
</ul>

No need for any tweak, you got a native API:

const toNodes = html =>
    new DOMParser().parseFromString(html, 'text/html').body.childNodes[0]

For certain html fragments like <td>test</td>, div.innerHTML, DOMParser.parseFromString and range.createContextualFragment (without the right context) solutions mentioned in other answers here, won't create the <td> element.

jQuery.parseHTML() handles them properly (I extracted jQuery 2's parseHTML function into an independent function that can be used in non-jquery codebases).

If you are only supporting Edge 13+, it is simpler to just use the HTML5 template tag:

function parseHTML(html) {
    var t = document.createElement('template');
    t.innerHTML = html;
    return t.content;
}

var documentFragment = parseHTML('<td>Test</td>');

Newer DOM implementations have range.createContextualFragment, which does what you want in a framework-independent way.

It's widely supported. To be sure though, check its compatibility down in the same MDN link, as it will be changing. As of May 2017 this is it:

Feature         Chrome   Edge   Firefox(Gecko)  Internet Explorer   Opera   Safari
Basic support   (Yes)    (Yes)  (Yes)           11                  15.0    9.1.2

Heres a simple way to do it:

String.prototype.toDOM=function(){
  var d=document
     ,i
     ,a=d.createElement("div")
     ,b=d.createDocumentFragment();
  a.innerHTML=this;
  while(i=a.firstChild)b.appendChild(i);
  return b;
};

var foo="<img src='//placekitten.com/100/100'>foo<i>bar</i>".toDOM();
document.body.appendChild(foo);

You can create valid DOM nodes from a string using:

document.createRange().createContextualFragment()

The following example adds a button element in the page taking the markup from a string:

let html = '<button type="button">Click Me!</button>';
let fragmentFromString = function (strHTML) {
  return document.createRange().createContextualFragment(strHTML);
}
let fragment = fragmentFromString(html);
document.body.appendChild(fragment);

I am using this method (Works in IE9+), although it will not parse <td> or some other invalid direct childs of body:

function stringToEl(string) {
    var parser = new DOMParser(),
        content = 'text/html',
        DOM = parser.parseFromString(string, content);

    // return element
    return DOM.body.childNodes[0];
}

stringToEl('<li>text</li>'); //OUTPUT: <li>text</li>

I added a Document prototype that creates an element from string:

Document.prototype.createElementFromString = function (str) {
   const element = new DOMParser().parseFromString(str, 'text/html');
   const child = element.documentElement.querySelector('body').firstChild;
   return child;
};

Usage:

document.createElementFromString("<h1>Hello World!</h1>");

Why don't do with native js?

    var s="<span class='text-muted' style='font-size:.75em; position:absolute; bottom:3px; left:30px'>From <strong>Dan's Tools</strong></span>"
    var e=document.createElement('div')
    var r=document.createRange();
    r.selectNodeContents(e)
    var f=r.createContextualFragment(s);
    e.appendChild(f);
    e = e.firstElementChild;

Answer

• Create a Template
• Set the Template's innerHTML to your string .trim()
• Create an Array of Template's children
• Return children, child, or

function toElement(s='',c,t=document.createElement('template'),l='length'){
t.innerHTML=s.trim();c=[...t.content.childNodes];return c[l]>1?c:c[0]||'';}



console.log(toElement());
console.log(toElement(''));
console.log(toElement('    '));
console.log(toElement('<td>With td</td>'));
console.log(toElement('<tr><td>With t</td></tr>'));
console.log(toElement('<tr><td>foo</td></tr><tr><td>bar</td></tr>'));
console.log(toElement('<div><span>nested</span> <span>stuff</span></div>'));

Solution - works with all browsers since IE 4.0

var htmlString = `<body><header class="text-1">Hello World</header><div id="table"><!--TABLE HERE--></div></body>`;
var tableString = `<table class="table"><thead><tr><th>th cell</th></tr></thead><tbody><tr><td>td cell</td></tr></tbody></table>`;


var doc = document.implementation.createHTMLDocument();
    doc.open();
    doc.write(htmlString);
    doc.getElementById('table').insertAdjacentHTML('beforeend', tableString);
    doc.close();

console.log(doc);

Or you can use DOMParser

var doc = (new DOMParser).parseFromString(htmlString, "text/html");
    doc.getElementById('table').insertAdjacentHTML('beforeend', tableString);

console.log(doc);

HTML5 & ES6

<template>

Demo

"use strict";

/**
 *
 * @author xgqfrms
 * @license MIT
 * @copyright xgqfrms
 * @description HTML5 Template
 * @augments
 * @example
 *
 */

/*

<template>
    <h2>Flower</h2>
    <img src="https://www.w3schools.com/tags/img_white_flower.jpg">
</template>


<template>
    <div class="myClass">I like: </div>
</template>

*/

const showContent = () => {
    // let temp = document.getElementsByTagName("template")[0],
    let temp = document.querySelector(`[data-tempalte="tempalte-img"]`),
        clone = temp.content.cloneNode(true);
    document.body.appendChild(clone);
};

const templateGenerator = (datas = [], debug = false) => {
    let result = ``;
    // let temp = document.getElementsByTagName("template")[1],
    let temp = document.querySelector(`[data-tempalte="tempalte-links"]`),
        item = temp.content.querySelector("div");
    for (let i = 0; i < datas.length; i++) {
        let a = document.importNode(item, true);
        a.textContent += datas[i];
        document.body.appendChild(a);
    }
    return result;
};

const arr = ["Audi", "BMW", "Ford", "Honda", "Jaguar", "Nissan"];

if (document.createElement("template").content) {
    console.log("YES! The browser supports the template element");
    templateGenerator(arr);
    setTimeout(() => {
        showContent();
    }, 0);
} else {
    console.error("No! The browser does not support the template element");
}

@charset "UTf-8";

/* test.css */

:root {
    --cololr: #000;
    --default-cololr: #fff;
    --new-cololr: #0f0;
}

[data-class="links"] {
    color: white;
    background-color: DodgerBlue;
    padding: 20px;
    text-align: center;
    margin: 10px;
}

<!DOCTYPE html>
<html lang="zh-Hans">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Template Test</title>
    <!--[if lt IE 9]>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/html5shiv/3.7.3/html5shiv.js"></script>
    <![endif]-->
</head>

<body>
    <section>
        <h1>Template Test</h1>
    </section>
    <template data-tempalte="tempalte-img">
        <h3>Flower Image</h3>
        <img src="https://www.w3schools.com/tags/img_white_flower.jpg">
    </template>
    <template data-tempalte="tempalte-links">
        <h3>links</h3>
        <div data-class="links">I like: </div>
    </template>
    <!-- js -->
</body>

</html>

Here's how to do it with PrototypeJS (as originally requested by the OP 12 years ago):

HTML:

<ul id="mylist"></ul>

JS:

$('mylist').insert('<li>text</li>');

Note that this is not jQuery!

Late but just as a note;

It's possible to add a trivial element to target element as a container and remove it after using.

// Tested on chrome 23.0, firefox 18.0, ie 7-8-9 and opera 12.11.

<div id="div"></div>

<script>
window.onload = function() {
    var foo, targetElement = document.getElementById('div')
    foo = document.createElement('foo')
    foo.innerHTML = '<a href="#" target="_self">Text of A 1.</a> '+
                    '<a href="#" onclick="return !!alert(this.innerHTML)">Text of <b>A 2</b>.</a> '+
                    '<hr size="1" />'
    // Append 'foo' element to target element
    targetElement.appendChild(foo)

    // Add event
    foo.firstChild.onclick = function() { return !!alert(this.target) }

    while (foo.firstChild) {
        // Also removes child nodes from 'foo'
        targetElement.insertBefore(foo.firstChild, foo)
    }
    // Remove 'foo' element from target element
    targetElement.removeChild(foo)
}
</script>

Fastest solution to render DOM from string:

let render = (relEl, tpl, parse = true) => {
  if (!relEl) return;
  const range = document.createRange();
  range.selectNode(relEl);
  const child = range.createContextualFragment(tpl);
  return parse ? relEl.appendChild(child) : {relEl, el};
};

And here u can check performance for DOM manipulation React vs native JS

Now u can simply use:

let element = render(document.body, `
<div style="font-size:120%;line-height:140%">
  <p class="bold">New DOM</p>
</div>
`);

And of course in near future u use references from memory cause var "element" is your new created DOM in your document.

And remember "innerHTML=" is very slow :/

Here's my code, and it works:

function parseTableHtml(s) { // s is string
    var div = document.createElement('table');
    div.innerHTML = s;

    var tr = div.getElementsByTagName('tr');
    // ...
}

What about using outerHTML ?

*element*.appendChild( document.createElement('li')).outerHTML= '<li>text</li>' ;

The parameter for createElement doesn't need to match the element type specified in your string, but it does need to be a legal child of element

*element*.appendChild( document.createElement('a')).outerHTML= '<li>text</li>' ;

works just as well

For the heck of it I thought I'd share this over complicated but yet simple approach I came up with... Maybe someone will find something useful.

/*Creates a new element - By Jamin Szczesny*/
function _new(args){
    ele = document.createElement(args.node);
    delete args.node;
    for(x in args){ 
        if(typeof ele[x]==='string'){
            ele[x] = args[x];
        }else{
            ele.setAttribute(x, args[x]);
        }
    }
    return ele;
}

/*You would 'simply' use it like this*/

$('body')[0].appendChild(_new({
    node:'div',
    id:'my-div',
    style:'position:absolute; left:100px; top:100px;'+
          'width:100px; height:100px; border:2px solid red;'+
          'cursor:pointer; background-color:HoneyDew',
    innerHTML:'My newly created div element!',
    value:'for example only',
    onclick:"alert('yay')"
}));

I have searched a lot for this myself and came across this solution which is neat.

const stringToHTML = (str) => {
    var parser = new DOMParser();
    var doc = parser.parseFromString(str, 'text/html');
    return doc.body;
};

String that I wanted to convert:

'<iframe src="https://player.vimeo.com/video/578680903?h=ea840f9223&amp;app_id=122963" width="640" height="360" frameborder="0" allow="autoplay; fullscreen; picture-in-picture" allowfullscreen title="Total Body Balance"></iframe>'

The result:

<body><iframe src="https://player.vimeo.com/video/578680903?h=ea840f9223&amp;app_id=122963" width="640" height="360" frameborder="0" allow="autoplay; fullscreen; picture-in-picture" allowfullscreen="" title="Total Body Balance"></iframe></body>

Visit https://www.codegrepper.com/code-examples/javascript/convert+a+string+to+html+element+in+js

const stringToHtml = function (str) {
    var parser = new DOMParser();
    var doc = parser.parseFromString(str, 'text/html');
    return doc.body;
}

function domify (str) {
  var el = document.createElement('div');
  el.innerHTML = str;

  var frag = document.createDocumentFragment();
  return frag.appendChild(el.removeChild(el.firstChild));
}

var str = "<div class='foo'>foo</div>";
domify(str);

I've linked from this article.^{( Converting HTML string into DOM elements? )}

For me, I want to find a way to convert a string into an HTML element. If you also have this need, you can try the following

const frag = document.createRange().createContextualFragment(
`<a href="/link.js">js</a> 
 <a>go</a>
`
) 
const aCollection = frag.querySelectorAll("a")
for (let [key, a] of Object.entries(aCollection)) {
  console.log(a.getAttribute("href"), a.textContent)
}

Example with latest JS:

<template id="woof-sd-feature-box">
<div class="woof-sd-feature-box" data-key="__KEY__" data-title="__TITLE__" data-data="__OPTIONS__">
    <h4>__TITLE__</h4>
    <div class="woof-sd-form-item-anchor">
        <img src="img/move.png" alt="">
    </div>
</div>

</template>

<script>
create(example_object) {
        let html = document.getElementById('woof-sd-feature-box').innerHTML;
        html = html.replaceAll('__KEY__', example_object.dataset.key);
        html = html.replaceAll('__TITLE__', example_object.dataset.title);
        html = html.replaceAll('__OPTIONS__', example_object.dataset.data);
        //convertion HTML to DOM element and prepending it into another element
        const dom = (new DOMParser()).parseFromString(html, "text/html");
        this.container.prepend(dom.querySelector('.woof-sd-feature-box'));
    }
</script>

You can use the following function to convert the text "HTML" to the element

function htmlToElement(html)
{
  var element = document.createElement('div');
  element.innerHTML = html;
  return(element);
}
var html="<li>text and html</li>";
var e=htmlToElement(html);