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HTML5 Boilerplate homepage | Documentation table of contents

Extend and customise HTML5 Boilerplate

Here is some useful advice for how you can make your project with HTML5 Boilerplate even better. We don't want to include it all by default, as not everything fits with everyone's needs.

DNS prefetching

In short, DNS Prefetching is a method of informing the browser of domain names referenced on a site so that the client can resolve the DNS for those hosts, cache them, and when it comes time to use them, have a faster turn around on the request.

Implicit prefetches

There is a lot of prefetching done for you automatically by the browser. When the browser encounters an anchor in your html that does not share the same domain name as the current location the browser requests, from the client OS, the IP address for this new domain. The client first checks its cache and then, lacking a cached copy, makes a request from a DNS server. These requests happen in the background and are not meant to block the rendering of the page.

The goal of this is that when the foreign IP address is finally needed it will already be in the client cache and will not block the loading of the foreign content. Less requests result in faster page load times. The perception of this is increased on a mobile platform where DNS latency can be greater.

Disable implicit prefetching

<meta http-equiv="x-dns-prefetch-control" content="off">

Even with X-DNS-Prefetch-Control meta tag (or http header) browsers will still prefetch any explicit dns-prefetch links.

WARNING: THIS MAY MAKE YOUR SITE SLOWER IF YOU RELY ON RESOURCES FROM FOREIGN DOMAINS.

Explicit prefetches

Typically the browser only scans the HTML for foreign domains. If you have resources that are outside of your HTML (a javascript request to a remote server or a CDN that hosts content that may not be present on every page of your site, for example) then you can queue up a domain name to be prefetched.

<link rel="dns-prefetch" href="//example.com">
<link rel="dns-prefetch" href="//ajax.googleapis.com">

You can use as many of these as you need, but it's best if they are all immediately after the Meta Charset element (which should go right at the top of the head), so the browser can act on them ASAP.

Common Prefetch Links

Amazon S3:

<link rel="dns-prefetch" href="//s3.amazonaws.com">

Google APIs:

<link rel="dns-prefetch" href="//ajax.googleapis.com">

Microsoft Ajax Content Delivery Network:

<link rel="dns-prefetch" href="//ajax.microsoft.com">
<link rel="dns-prefetch" href="//ajax.aspnetcdn.com">

Browser support for DNS prefetching

Chrome, Firefox 3.5+, Safari 5+, Opera (Unknown), IE 9 (called "Pre-resolution" on blogs.msdn.com)

Further reading about DNS prefetching

Search

Direct search spiders to your sitemap

Learn how to make a sitemap

<link rel="sitemap" type="application/xml" title="Sitemap" href="/sitemap.xml">

Hide pages from search engines

According to Heather Champ, former community manager at Flickr, you should not allow search engines to index your "Contact Us" or "Complaints" page if you value your sanity. This is an HTML-centric way of achieving that.

<meta name="robots" content="noindex">

WARNING: DO NOT INCLUDE ON PAGES THAT SHOULD APPEAR IN SEARCH ENGINES.

Firefox and IE Search Plugins

Sites with in-site search functionality should be strongly considered for a browser search plugin. A "search plugin" is an XML file which defines how your plugin behaves in the browser. How to make a browser search plugin.

<link rel="search" title="" type="application/opensearchdescription+xml" href="">

Internet Explorer

Prompt users to switch to "Desktop Mode" in IE10 Metro

IE10 does not support plugins, such as Flash, in Metro mode. If your site requires plugins, you can let users know that via the X-UA-Compatible meta element, which will prompt them to switch to Desktop Mode.

<meta http-equiv="X-UA-Compatible" content="requiresActiveX=true">

Here's what it looks like alongside H5BP's default X-UA-Compatible values:

<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1,requiresActiveX=true">

You can find more information in Microsoft's IEBlog post about prompting for plugin use in IE10 Metro Mode.

IE Pinned Sites (IE9+)

Enabling your application for pinning will allow IE9 users to add it to their Windows Taskbar and Start Menu. This comes with a range of new tools that you can easily configure with the elements below. See more documentation on IE9 Pinned Sites.

Name the Pinned Site for Windows

Without this rule, Windows will use the page title as the name for your application.

<meta name="application-name" content="Sample Title">

Give your Pinned Site a tooltip

You know — a tooltip. A little textbox that appears when the user holds their mouse over your Pinned Site's icon.

<meta name="msapplication-tooltip" content="A description of what this site does.">

Set a default page for your Pinned Site

If the site should go to a specific URL when it is pinned (such as the homepage), enter it here. One idea is to send it to a special URL so you can track the number of pinned users, like so: http://www.example.com/index.html?pinned=true

<meta name="msapplication-starturl" content="http://www.example.com/index.html?pinned=true">

Recolor IE's controls manually for a Pinned Site

IE9+ will automatically use the overall color of your Pinned Site's favicon to shade its browser buttons. UNLESS you give it another color here. Only use named colors (red) or hex colors (#ff0000).

<meta name="msapplication-navbutton-color" content="#ff0000">

Manually set the window size of a Pinned Site

If the site should open at a certain window size once pinned, you can specify the dimensions here. It only supports static pixel dimensions. 800x600 minimum.

<meta name="msapplication-window" content="width=800;height=600">

Jump List "Tasks" for Pinned Sites

Add Jump List Tasks that will appear when the Pinned Site's icon gets a right-click. Each Task goes to the specified URL, and gets its own mini icon (essentially a favicon, a 16x16 .ICO). You can add as many of these as you need.

<meta name="msapplication-task" content="name=Task 1;action-uri=http://host/Page1.html;icon-uri=http://host/icon1.ico">
<meta name="msapplication-task" content="name=Task 2;action-uri=http://microsoft.com/Page2.html;icon-uri=http://host/icon2.ico">

(Windows 8) High quality visuals for Pinned Sites

Windows 8 adds the ability for you to provide a PNG tile image and specify the tile's background color. Full details on the IE blog.

  • Create a 144x144 image of your site icon, filling all of the canvas, and using a transparent background.
  • Save this image as a 32-bit PNG and optimize it without reducing colour-depth. It can be named whatever you want (e.g. metro-tile.png).
  • To reference the tile and its color, add the HTML meta elements described in the IE Blog post.

(Windows 8) Badges for Pinned Sites

IE10 will poll an XML document for badge information to display on your app's tile in the Start screen. The user will be able to receive these badge updates even when your app isn't actively running. The badge's value can be a number, or one of a predefined list of glyphs.

<meta name="msapplication-badge" value="frequency=NUMBER_IN_MINUTES;polling-uri=http://www.example.com/path/to/file.xml">

Disable link highlighting upon tap in IE10

Similar to -webkit-tap-highlight-color in iOS Safari. Unlike that CSS property, this is an HTML meta element, and it's value is boolean rather than a color. It's all or nothing.

<meta name="msapplication-tap-highlight" content="no" />

You can read about this useful element and more techniques in Microsoft's documentation on adapting WebKit-oriented apps for IE10.

Suppress IE6 image toolbar

Kill IE6's pop-up-on-mouseover toolbar for images that can interfere with certain designs and be pretty distracting in general.

<meta http-equiv="imagetoolbar" content="false">

Social Networks

Facebook Open Graph data

You can control the information that Facebook and others display when users share your site. Below are just the most basic data points you might need. For specific content types (including "website"), see Facebook's built-in Open Graph content templates. Take full advantage of Facebook's support for complex data and activity by following the Open Graph tutorial.

<meta property="og:title" content="">
<meta property="og:description" content="">
<meta property="og:image" content="">

Twitter Cards

Twitter provides a snippet specification that serves a similar purpose to Open Graph. In fact, Twitter will use Open Graph when Cards is not available. Note that, as of this writing, Twitter requires that app developers activate Cards on a per-domain basis. You can read more about the various snippet formats and application process in the official Twitter Cards documentation.

<meta name="twitter:card" content="summary">
<meta name="twitter:site" content="@site_account">
<meta name="twitter:creator" content="@individual_account">
<meta name="twitter:url" content="http://www.example.com/path/to/page.html">
<meta name="twitter:title" content="">
<meta name="twitter:description" content="">
<meta name="twitter:image" content="http://www.example.com/path/to/image.jpg">

URLs

Canonical URL

Signal to search engines and others "Use this URL for this page!" Useful when parameters after a # or ? is used to control the display state of a page. http://www.example.com/cart.html?shopping-cart-open=true can be indexed as the cleaner, more accurate http://www.example.com/cart.html.

<link rel="canonical" href="">

Official shortlink

Signal to the world "This is the shortened URL to use this page!" Poorly supported at this time. Learn more by reading the article about shortlinks on the Microformats wiki.

<link rel="shortlink" href="h5bp.com">

News Feeds

RSS

Have an RSS feed? Link to it here. Want to learn how to write an RSS feed from scratch?

<link rel="alternate" type="application/rss+xml" title="RSS" href="/rss.xml">

Atom

Atom is similar to RSS, and you might prefer to use it instead of or in addition to it. See what Atom's all about.

<link rel="alternate" type="application/atom+xml" title="Atom" href="/atom.xml">

Pingbacks

Your server may be notified when another site links to yours. The href attribute should contain the location of your pingback service.

<link rel="pingback" href="">

App Stores

Install a Chrome Web Store app

Users can install a Chrome app directly from your website, as long as the app and site have been associated via Google's Webmaster Tools. Read more on Chrome Web Store's Inline Installation docs.

<link rel="chrome-webstore-item" href="https://chrome.google.com/webstore/detail/APP_ID">

Smart App Banners in iOS 6 Safari

Stop bothering everyone with gross modals advertising your entry in the App Store. This bit of code will unintrusively allow the user the option to download your iOS app, or open it with some data about the user's current state on the website.

<meta name="apple-itunes-app" content="app-id=APP_ID,app-argument=SOME_TEXT">

Google Analytics augments

More tracking settings

The optimized Google Analytics snippet included with HTML5 Boilerplate includes something like this:

var _gaq = [['_setAccount', 'UA-XXXXX-X'], ['_trackPageview']];

In case you need more settings, just extend the array literal instead of .push()ing to the array afterwards:

var _gaq = [['_setAccount', 'UA-XXXXX-X'], ['_trackPageview'], ['_setAllowAnchor', true]];

Anonymize IP addresses

In some countries, no personal data may be transferred outside jurisdictions that do not have similarly strict laws (i.e. from Germany to outside the EU). Thus a webmaster using the Google Analytics script may have to ensure that no personal (trackable) data is transferred to the US. You can do that with the _gat.anonymizeIp option. In use it looks like this:

var _gaq = [['_setAccount', 'UA-XXXXX-X'], ['_gat._anonymizeIp'], ['_trackPageview']];

Track jQuery AJAX requests in Google Analytics

An article by @JangoSteve explains how to track jQuery AJAX requests in Google Analytics.

Add this to plugins.js:

/*
 * Log all jQuery AJAX requests to Google Analytics
 * See: http://www.alfajango.com/blog/track-jquery-ajax-requests-in-google-analytics/
 */
if (typeof _gaq !== "undefined" && _gaq !== null) {
    $(document).ajaxSend(function(event, xhr, settings){
        _gaq.push(['_trackPageview', settings.url]);
    });
}

Track JavaScript errors in Google Analytics

Add this function after _gaq is defined:

(function(window){
    var undefined,
        link = function (href) {
            var a = window.document.createElement('a');
            a.href = href;
            return a;
        };
    window.onerror = function (message, file, line, column) {
        var host = link(file).hostname;
        _gaq.push([
            '_trackEvent',
            (host == window.location.hostname || host == undefined || host == '' ? '' : 'external ') + 'error',
            message, file + ' LINE: ' + line + (column ? ' COLUMN: ' + column : ''), undefined, undefined, true
        ]);
    };
}(window));

Track page scroll

Add this function after _gaq is defined:

$(function(){
    var isDuplicateScrollEvent,
        scrollTimeStart = new Date,
        $window = $(window),
        $document = $(document),
        scrollPercent;

    $window.scroll(function() {
        scrollPercent = Math.round(100 * ($window.height() + $window.scrollTop())/$document.height());
        if (scrollPercent > 90 && !isDuplicateScrollEvent) { //page scrolled to 90%
            isDuplicateScrollEvent = 1;
            _gaq.push(['_trackEvent', 'scroll',
                'Window: ' + $window.height() + 'px; Document: ' + $document.height() + 'px; Time: ' + Math.round((new Date - scrollTimeStart )/1000,1) + 's',
                undefined, undefined, true
            ]);
        }
    });
});

iOS Web Apps

There are a couple of meta tags that provide information about a web app when added to the Home Screen on iOS.

Adding apple-mobile-web-app-capable will make your web app chrome-less and provide the default iOS app view. You can control the color scheme of the default view by adding apple-mobile-web-app-status-bar-style.

<meta name="apple-mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-status-bar-style" content="black">

You can use apple-mobile-web-app-title to add a specific sites name for the Home Screen icon. This works since iOS 6.

<meta name="apple-mobile-web-app-title" content="">

For further information please read the official documentation on Apple's site.

Apple Touch Icons

Touch Icons can be seen as the favicons of mobile devices and tablets.

If your site or icons are in a sub-directory, you will need to reference the icons using link elements placed in the HTML head of your document.

<link rel="apple-touch-icon-precomposed" href="apple-touch-icon-precomposed.png">

The main sizes of the icons on iOS are:

  • iPad, high-resolution display, iOS 7: 152x152
  • iPad, high-resolution display, iOS ≤ 6: 144x144
  • iPhone, high-resolution display, iOS 7: 120x120
  • iPhone, high-resolution display, iOS ≤ 6: 114x114
  • iPad, non-Retina, iOS ≤ 6: 72x72

For non-Retina iPhone, iPod Touch, and Android 2.1+ devices you can use the example from above or replace the apple-touch-icon-precomposed.png within this project's root folder.

Please refer to Mathias' article on Touch Icons for a comprehensive overview.

Apple Touch Startup Image

Apart from that it is possible to add start-up screens for web apps on iOS. This basically works by defining apple-touch-startup-image with an according link to the image. Since iOS devices have different screen resolutions it is necessary to add media queries to detect which image to load. Here is an example for a retina iPhone:

<link rel="apple-touch-startup-image" media="(max-device-width: 480px) and (-webkit-min-device-pixel-ratio: 2)" href="img/startup-retina.png">

However, it is possible to detect which start-up image to use with JavaScript. The Mobile Boilerplate provides a useful function for this. Please see helpers.js for the implementation.

Miscellaneous

Many thanks to Brian Blakely for contributing much of this information.