Is it necessary to write HEAD, BODY and HTML tags?

Html Problem Overview

Is it necessary to write <html>, <head> and <body> tags?

For example, I can make such a page:

<!DOCTYPE html>
    <meta http-equiv="Content-type" content="text/html; charset=utf-8">
    <title>Page Title</title>
    <link rel="stylesheet" type="text/css" href="css/reset.css">
    <script src="js/head_script.js"></script><!-- this script will be in head //-->


<div>Some html</div> <!-- here body starts //-->

    <script src="js/body_script.js"></script>

And Firebug correctly separates head and body:

Enter image description here

The W3C validator says it's valid.

But I rarely see this practice on the web.

Is there a reason to write these tags?

Html Solutions

Solution 1 - Html

Omitting the html, head, and body tags is certainly allowed by the HTML specifications. The underlying reason is that browsers have always sought to be consistent with existing web pages, and the very early versions of HTML didn't define those elements. When HTML first did, it was done in a way that the tags would be inferred when missing.

I often find it convenient to omit the tags when prototyping and especially when writing test cases as it helps keep the markup focused on the test in question. The inference process should create the elements in exactly the manner that you see in Firebug, and browsers are pretty consistent in doing that.

But...

Internet Explorer has at least one known bug in this area. Even Internet Explorer 9 exhibits this. Suppose the markup is this:

<!DOCTYPE html>
<title>Test case</title>
<form action='#'>
   <input name="var1">
</form>

You should (and do in other browsers) get a DOM that looks like this:

HTML
    HEAD
        TITLE
    BODY
        FORM action="#"
            INPUT name="var1"

But in Internet Explorer you get this:

HTML
    HEAD
       TITLE
       FORM action="#"
           BODY
               INPUT name="var1"
    BODY

See it for yourself.

This bug seems limited to the form start tag preceding any text content and any body start tag.

Solution 2 - Html

The Google Style Guide for HTML recommends omitting all optional tags. That includes <html>, <head>, <body>, <p> and <li>.

From 3.1.7 Optional Tags:

> For file size optimization and scannability purposes, consider > omitting optional tags. The HTML5 specification defines what tags can > be omitted. > > (This approach may require a grace period to be established as a wider > guideline as it’s significantly different from what web developers are > typically taught. For consistency and simplicity reasons it’s best > served omitting all optional tags, not just a selection.) > > > > > > Spending money, spending bytes > > >

Sic.

> > > > > > Saving money, saving bytes >

Qed.

Solution 3 - Html

Contrary to Liza Daly's note about HTML5, that specification is actually quite specific about which tags can be omitted, and when (and the rules are a bit different from HTML 4.01, mostly to clarify where ambiguous elements like comments and whitespace belong)

The relevant reference is 8.1.2.4 Optional tags, and it says:

An html element's start tag may be omitted if the first thing inside the html element is not a comment.
An html element's end tag may be omitted if the html element is not immediately followed by a comment.
A head element's start tag may be omitted if the element is empty, or if the first thing inside the head element is an element.
A head element's end tag may be omitted if the head element is not immediately followed by a space character or a comment.
A body element's start tag may be omitted if the element is empty, or if the first thing inside the body element is not a space character or a comment, except if the first thing inside the body element is a script or style element.
A body element's end tag may be omitted if the body element is not immediately followed by a comment.

So your example is valid HTML5, and would be parsed like this, with the html, head and body tags in their implied positions:

<!DOCTYPE html><HTML><HEAD>
    <meta http-equiv="Content-type" content="text/html; charset=utf-8">
    <title>Page Title</title>
    <link rel="stylesheet" type="text/css" href="css/reset.css">
    <script src="js/head_script.js"></script></HEAD><BODY><!-- this script will be in head //-->


<div>Some HTML content</div> <!-- here body starts //-->

    <script src="js/body_script.js"></script></BODY></HTML>

Note that the comment "this script will be in head" is actually parsed as part of the body, although the script itself is part of the head. According to the specification, if you want that to be different at all, then the </HEAD> and <BODY> tags may not be omitted. (Although the corresponding <HEAD> and </BODY> tags still can be.)

Solution 4 - Html

It's valid to omit them in HTML 4:

> 7.3 The HTML element
> start tag: optional, End tag: optional
>
7.4.1 The HEAD element
> start tag: optional, End tag: optional

From 7 The global structure of an HTML document.

In HTML5, there are no "required" or "optional" elements exactly, as HTML5 syntax is more loosely defined. For example, title:

> The title element is a required child in most situations, but when a higher-level protocol provides title information, e.g. in the Subject line of an e-mail when HTML is used as an e-mail authoring format, the title element can be omitted.

From 4.2.2 The title element.

It's not valid to omit them in true XHTML5, though that is almost never used (versus XHTML-acting-like-HTML5).

However, from a practical standpoint you often want browsers to run in "standards mode," for predictability in rendering HTML and CSS. Providing a DOCTYPE and a more structured HTML tree will guarantee more predictable cross-browser results.

Solution 5 - Html

It's true that the HTML specifications permit certain tags to be omitted in certain cases, but generally doing so is unwise.

It has two effects - it makes the specification more complex, which in turn makes it harder for browser authors to write correct implementations (as demonstrated by Internet Explorer getting it wrong).

This makes the likelihood of browser errors in these parts of the specification high. As a website author, you can avoid the issue by including these tags - so while the specification doesn't say you have to, doing so reduces the chance of things going wrong, which is good engineering practice.

What's more, the latest HTML 5.1 WG specification currently says (bear in mind it’s a work in progress and may yet change).

> A body element's start tag may be omitted if the element is empty, or > if the first thing inside the body element is not a space character or > a comment, except if the first thing inside the body element is a > meta, link, script, style, or template element.

From 4.3.1 The body element.

This is a little subtle. You can omit body and head, and the browser will then infer where those elements should be inserted. This carries the risk of not being explicit, which could cause confusion.

So this

<html>
  <h1>hello</h1>
  <script ... >
  ...

results in the script element being a child of the body element, but this

<html>
  <script ... >
  <h1>hello</h1>

would result in the script tag being a child of the head element.

You could be explicit by doing this:

<html>
    <body>
      <script ... >
      <h1>hello</h1>

and then whichever you have first, the script or the h1, they will both, predictably appear in the body element. These are things which are easy to overlook while refactoring and debugging code (say for example, you have JavaScript which is looking for the 1st script element in the body - in the second snippet it would stop working).

As a general rule, being explicit about things is always better than leaving things open to interpretation. In this regard, XHTML is better, because it forces you to be completely explicit about your element structure in your code, which makes it simpler, and therefore less prone to misinterpretation.

So yes, you can omit them and be technically valid, but it is generally unwise to do so.

Solution 6 - Html

Firebug shows this correctly because your browser automagically fixes the bad markup for you. This behaviour is not specified anywhere and can (will) vary from browser to browser. Those tags are required by the DOCTYPE you're using and should not be omitted.

The HTML element is the root element of every html page. If you look at all other elements' description it says where an element can be used (and almost all elements require either head or body).

Content Type	Original Author	Original Content on Stackoverflow
Question	Larry Cinnabar	View Question on Stackoverflow
Solution 1 - Html	Alohci	View Answer on Stackoverflow
Solution 2 - Html	Rima	View Answer on Stackoverflow
Solution 3 - Html	Ian Clelland	View Answer on Stackoverflow
Solution 4 - Html	Liza Daly	View Answer on Stackoverflow
Solution 5 - Html	Peter Bagnall	View Answer on Stackoverflow
Solution 6 - Html	halfdan	View Answer on Stackoverflow