can use anything in any order? does placing of <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
is important before <title>
this is most used, is it best way?
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<title>Title Goes Here</title>
<link rel="stylesheet" href="http://sstatic.net/so/all.css?v=5912">
<link rel="shortcut icon" href="http://sstatic.net/so/favicon.ico">
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
<script type="text/javascript">
$(function() {
$("#wmd-input").focus();
$("#title").focus();
$("#revisions-list").change(function() { window.location = '/posts/1987065/edit/' + $(this).val(); });
});
</script>
</head>
<body>
<p>This is my web page</p>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/mootools.js"></script>
</body>
</html>
this site http://stackoverflow.com doesn't have any encoding and <meta>
I use a CMS which has SEO component which adds every <meta>
for SEO after all js and css. files. can placing of any elements in any order which are allowed in <head>
affect document compatibility and encoding?
IIRC, some browsers will re-load the document upon encountering a
content-type
element. So that element should probably come first within thehead
element of the document.Adding a few performance suggestions to Brian's answer, highest priority should logically be things that will need to be downloaded, so the browser can start downloading them asap, and things that will affect how the page is presented. So I'd suggest:
You might also consider inlining whatever CSS and JS is loaded in head, especially if its small and the external script/sheet is unlikely to be cached according to your typical visitor's profile. And if you do inline it, you'll ideally want to compress it.
Last thing: The user has to wait around for head - and any blocking resources it loads - so it's best to put as much as possible in the body or footer.
You want your content-type first as this denotes the character encoding, otherwise if it comes later on, some browsers attempt to guess the encoding. (I can't remember the specifics, but I think IE will guess if it doesn't find an encoding in the first 75 characters of the document?)
Most webservers send the encoding in the HTTP headers, but if a user saves your page, the headers aren't saved with it.
I'd put CSS references second so the browser downloads them as soon as possible.
JavaScript I wouldn't put in the head, it should go at the bottom of your pages as downloading them blocks rendering of pages.
According to W3 should be:
This is the template I use, just delete whatever you dont need for a new project.
In HTML, the
DOCTYPE
must come first, followed by a single<html>
element, which must contain a<head>
element containing a<title>
element, followed by a<body>
element. See the description of the global structure of an HTML document in HTML 4.01 and the HTML5 draft; the actual requirements are mostly the same other than theDOCTYPE
, but they are described differently.The actual tags (
<html>
,</html>
,<head>
, etc) are optional; the elements will be created automatically if the tags don't exist.<title>
is the only required tag in HTML. The shortest valid HTML 4.01 document (at least, that I could generate) is (needs a<p>
because there needs to be something in the<body>
to be valid):And the shortest valid HTML5 document:
Note that in XHTML, all tags must be specified explicitly; no elements will be inserted implicitly.
Browsers perform content type sniffing in some circumstances to determine the type of a resource that hasn't been specified using a
Content-Type
HTTP header, and also character encoding sniffing if theContent-Type
header hasn't been supplied or doesn't include acharset
(you should generally try to include these headers, and make sure that they are correct, but there are some circumstances in which you cannot, such as local files not transferred over HTTP). They only sniff a limited number of bytes at the beginning of the document for these purposes, though, so anything that is intended to affect the content sniffing or character encoding sniffing should be near the beginning of the document.For this reason, HTML5 specifies that any
meta
tag which is used to specify the character set (either<meta http-equiv="Content-type" content="text/html; charset=...">
or simply<meta charset=...>
) must be within the first 1024 bytes of the file in order to take effect. So, if you are going to include character encoding information within your document, you should put the tag early in the file, possibly even before the<title>
element. But recall that this tag is unnecessary if you properly specify aContent-type
header.In CSS, later style declarations take precedence over earlier ones, all else being equal. So, you should generally put the most generic style sheets that may be overridden earlier, and the more specific style sheets later.
For performance reasons, it can be a good idea to put scripts at the bottom of the page, right before the
</body>
, because loading scripts blocks the rendering of the page.Obviously,
<script>
tags should be ordered so that scripts that depend on each order have the dependencies loaded first.On the whole, other than the constraints I have already specified, the ordering of tags within
<head>
shouldn't matter too much, other than for readability. I tend to like to see the<title>
towards the top, and put the other<meta>
tags in some sort of logical order.Most of the time, the order you should put things into the body of an HTML document should be the order they should be displayed in, or the order they should be accessed. You can use CSS to rearrange things, but screen readers will generally read things in source order, search indexes will extract things in source order, and so on.