さまざまなデバイスに設定できるさまざまなアイコンやスプラッシュスクリーンさえあります。この回答では、それらすべてをサポートする方法について説明します。
これは、私が情報を収集した場所への関連リンクとともに使用したスニペットです。ASP.NET MVCボイラープレートプロジェクトテンプレートの詳細と詳細については、私のブログを参照してください。これらはすべて、すぐに組み込まれています（サンプル画像ファイルを含む）。
次のマークアップをHTMLヘッドに追加します。コメントアウトされたセクションは完全にオプションです。コメントされていないセクションは、すべてのアイコンの使用法をカバーすることをお勧めしますが。それがあなたを助けるコメントであるならば、ほとんど怖がらないでください。
<!-- Icons & Platform Specific Settings - Favicon generator used to generate the icons below http://realfavicongenerator.net/ -->
<!-- shortcut icon - It is best to add this icon to the root of your site and only use this link element if you move it somewhere else. This file contains the following sizes 16x16, 32x32 and 48x48. -->
<!--<link rel="shortcut icon" href="favicon.ico">-->
<!-- favicon-96x96.png - For Google TV. -->
<link rel="icon" type="image/png" href="https://stackoverflow.com/content/images/favicon-96x96.png" sizes="96x96">
<!-- favicon-16x16.png - The classic favicon, displayed in the tabs. -->
<link rel="icon" type="image/png" href="https://stackoverflow.com/content/images/favicon-16x16.png" sizes="16x16">
<!-- favicon-32x32.png - For Safari on Mac OS. -->
<link rel="icon" type="image/png" href="https://stackoverflow.com/content/images/favicon-32x32.png" sizes="32x32">
<!-- Android/Chrome -->
<!-- manifest-json - The location of the browser configuration file. It contains locations of icon files, name of the application and default device screen orientation. Note that the name field is mandatory.
https://developer.chrome.com/multidevice/android/installtohomescreen. -->
<link rel="manifest" href="https://stackoverflow.com/content/icons/manifest.json">
<!-- theme-color - The colour of the toolbar in Chrome M39+
http://updates.html5rocks.com/2014/11/Support-for-theme-color-in-Chrome-39-for-Android -->
<meta name="theme-color" content="#1E1E1E">
<!-- favicon-192x192.png - For Android Chrome M36 to M38 this HTML is used. M39+ uses the manifest.json file. -->
<link rel="icon" type="image/png" href="https://stackoverflow.com/content/icons/favicon-192x192.png" sizes="192x192">
<!-- mobile-web-app-capable - Run Android/Chrome version M31 to M38 in standalone mode, hiding the browser chrome. -->
<!-- <meta name="mobile-web-app-capable" content="yes"> -->
<!-- Apple Icons - You can move all these icons to the root of the site and remove these link elements, if you don't mind the clutter.
https://developer.apple.com/library/safari/documentation/AppleApplications/Reference/SafariHTMLRef/Introduction.html#//apple_ref/doc/uid/30001261-SW1 -->
<!-- apple-mobile-web-app-title - The name of the application if pinned to the IOS start screen. -->
<!--<meta name="apple-mobile-web-app-title" content="">-->
<!-- apple-mobile-web-app-capable - Hide the browsers user interface on IOS, when the app is run in 'standalone' mode. Any links to other pages that are clicked whilst your app is in standalone mode will launch the full Safari browser. -->
<!--<meta name="apple-mobile-web-app-capable" content="yes">-->
<!-- apple-mobile-web-app-status-bar-style - default/black/black-translucent Styles the IOS status bar. Using black-translucent makes it transparent and overlays it on top of your site, so make sure you have enough margin. -->
<!--<meta name="apple-mobile-web-app-status-bar-style" content="black">-->
<!-- apple-touch-icon-57x57.png - Android Stock Browser and non-Retina iPhone and iPod Touch -->
<link rel="apple-touch-icon" sizes="57x57" href="https://stackoverflow.com/content/images/apple-touch-icon-57x57.png">
<!-- apple-touch-icon-114x114.png - iPhone (with 2× display) iOS = 6 -->
<link rel="apple-touch-icon" sizes="114x114" href="https://stackoverflow.com/content/images/apple-touch-icon-114x114.png">
<!-- apple-touch-icon-72x72.png - iPad mini and the first- and second-generation iPad (1× display) on iOS = 6 -->
<link rel="apple-touch-icon" sizes="72x72" href="https://stackoverflow.com/content/images/apple-touch-icon-72x72.png">
<!-- apple-touch-icon-144x144.png - iPad (with 2× display) iOS = 6 -->
<link rel="apple-touch-icon" sizes="144x144" href="https://stackoverflow.com/content/images/apple-touch-icon-144x144.png">
<!-- apple-touch-icon-60x60.png - Same as apple-touch-icon-57x57.png, for non-retina iPhone with iOS7. -->
<link rel="apple-touch-icon" sizes="60x60" href="https://stackoverflow.com/content/images/apple-touch-icon-60x60.png">
<!-- apple-touch-icon-120x120.png - iPhone (with 2× and 3 display) iOS = 7 -->
<link rel="apple-touch-icon" sizes="120x120" href="https://stackoverflow.com/content/images/apple-touch-icon-120x120.png">
<!-- apple-touch-icon-76x76.png - iPad mini and the first- and second-generation iPad (1× display) on iOS = 7 -->
<link rel="apple-touch-icon" sizes="76x76" href="https://stackoverflow.com/content/images/apple-touch-icon-76x76.png">
<!-- apple-touch-icon-152x152.png - iPad 3+ (with 2× display) iOS = 7 -->
<link rel="apple-touch-icon" sizes="152x152" href="https://stackoverflow.com/content/images/apple-touch-icon-152x152.png">
<!-- apple-touch-icon-180x180.png - iPad and iPad mini (with 2× display) iOS = 8 -->
<link rel="apple-touch-icon" sizes="180x180" href="https://stackoverflow.com/content/images/apple-touch-icon-180x180.png">
<!-- Apple Startup Images - These are shown when the page is loading if the site is pinned https://gist.github.com/tfausak/2222823 -->
<!-- apple-touch-startup-image-1536x2008.png - iOS 6 & 7 iPad (retina, portrait) -->
<link rel="apple-touch-startup-image"
href="https://stackoverflow.com/content/images/apple-touch-startup-image-1536x2008.png"
media="(device-width: 768px) and (device-height: 1024px) and (orientation: portrait) and (-webkit-device-pixel-ratio: 2)">
<!-- apple-touch-startup-image-1496x2048.png - iOS 6 & 7 iPad (retina, landscape) -->
<link rel="apple-touch-startup-image"
href="https://stackoverflow.com/content/images/apple-touch-startup-image-1496x2048.png"
media="(device-width: 768px) and (device-height: 1024px) and (orientation: landscape) and (-webkit-device-pixel-ratio: 2)">
<!-- apple-touch-startup-image-768x1004.png - iOS 6 iPad (portrait) -->
<link rel="apple-touch-startup-image"
href="https://stackoverflow.com/content/images/apple-touch-startup-image-768x1004.png"
media="(device-width: 768px) and (device-height: 1024px) and (orientation: portrait) and (-webkit-device-pixel-ratio: 1)">
<!-- apple-touch-startup-image-748x1024.png - iOS 6 iPad (landscape) -->
<link rel="apple-touch-startup-image"
href="https://stackoverflow.com/content/images/apple-touch-startup-image-748x1024.png"
media="(device-width: 768px) and (device-height: 1024px) and (orientation: landscape) and (-webkit-device-pixel-ratio: 1)">
<!-- apple-touch-startup-image-640x1096.png - iOS 6 & 7 iPhone 5 -->
<link rel="apple-touch-startup-image"
href="https://stackoverflow.com/content/images/apple-touch-startup-image-640x1096.png"
media="(device-width: 320px) and (device-height: 568px) and (-webkit-device-pixel-ratio: 2)">
<!-- apple-touch-startup-image-640x920.png - iOS 6 & 7 iPhone (retina) -->
<link rel="apple-touch-startup-image"
href="https://stackoverflow.com/content/images/apple-touch-startup-image-640x920.png"
media="(device-width: 320px) and (device-height: 480px) and (-webkit-device-pixel-ratio: 2)">
<!-- apple-touch-startup-image-320x460.png - iOS 6 iPhone -->
<link rel="apple-touch-startup-image"
href="https://stackoverflow.com/content/images/apple-touch-startup-image-320x460.png"
media="(device-width: 320px) and (device-height: 480px) and (-webkit-device-pixel-ratio: 1)">
<!-- Windows 8 Icons - If you add an RSS feed, revisit this page and regenerate the browserconfig.xml file. You will then have a cool live tile!
browserconfig.xml - Windows 8.1 - Has been added to the root of the site. This points to the tile images and tile background colour. It contains the following images:
mstile-70x70.png - For Windows 8.1 / IE11.
mstile-144x144.png - For Windows 8 / IE10.
mstile-150x150.png - For Windows 8.1 / IE11.
mstile-310x310.png - For Windows 8.1 / IE11.
mstile-310x150.png - For Windows 8.1 / IE11.
See http://www.buildmypinnedsite.com/en and http://msdn.microsoft.com/en-gb/library/ie/dn255024%28v=vs.85%29.aspx. -->
<!-- application-name - Windows 8+ - The name of the application if pinned to the start screen. -->
<!--<meta name="application-name" content="">-->
<!-- msapplication-TileColor - Windows 8 - The tile colour which shows around your tile image (msapplication-TileImage). -->
<meta name="msapplication-TileColor" content="#5cb95c">
<!-- msapplication-TileImage - Windows 8 - The tile image. -->
<meta name="msapplication-TileImage" content="/content/images/mstile-144x144.png">
私のbrowserconfig.xmlファイル。上記の完全な説明。
<?xml version="1.0" encoding="utf-8"?>
<browserconfig>
<msapplication>
<tile>
<square70x70logo src="/Content/Images/mstile-70x70.png"/>
<square150x150logo src="/Content/Images/mstile-150x150.png"/>
<square310x310logo src="/Content/Images/mstile-310x310.png"/>
<wide310x150logo src="/Content/Images/mstile-310x150.png"/>
<TileColor>#5cb95c</TileColor>
</tile>
</msapplication>
</browserconfig>
manifest.jsonファイル。上記の完全な説明。
{
"name": "ASP.NET MVC Boilerplate (Required! Update This)",
"icons": [
{
"src": "\/Content\/icons\/android-chrome-36x36.png",
"sizes": "36x36",
"type": "image\/png",
"density": "0.75"
},
{
"src": "\/Content\/icons\/android-chrome-48x48.png",
"sizes": "48x48",
"type": "image\/png",
"density": "1.0"
},
{
"src": "\/Content\/icons\/android-chrome-72x72.png",
"sizes": "72x72",
"type": "image\/png",
"density": "1.5"
},
{
"src": "\/Content\/icons\/android-chrome-96x96.png",
"sizes": "96x96",
"type": "image\/png",
"density": "2.0"
},
{
"src": "\/Content\/icons\/android-chrome-144x144.png",
"sizes": "144x144",
"type": "image\/png",
"density": "3.0"
},
{
"src": "\/Content\/icons\/android-chrome-192x192.png",
"sizes": "192x192",
"type": "image\/png",
"density": "4.0"
}
]
}
プロジェクト内のファイルのリスト（これらのファイルの一部は、上記のメタタグの使用を避けるためにプロジェクトのルートに置くことにした場合に重要です）：
favicon.ico
browserconfig.xml
Content/Images/
android-chrome-144x144.png
android-chrome-192x192.png
android-chrome-36x36.png
android-chrome-48x48.png
android-chrome-72x72.png
android-chrome-96x96.png
apple-touch-icon.png
apple-touch-icon-57x57.png
apple-touch-icon-60x60.png
apple-touch-icon-72x72.png
apple-touch-icon-76x76.png
apple-touch-icon-114x114.png
apple-touch-icon-120x120.png
apple-touch-icon-144x144.png
apple-touch-icon-152x152.png
apple-touch-icon-180x180.png
apple-touch-icon-precomposed.png (180x180)
favicon-16x16.png
favicon-32x32.png
favicon-96x96.png
favicon-192x192.png
manifest.json
mstile-70x70.png
mstile-144x144.png
mstile-150x150.png
mstile-310x150.png
mstile-310x310.png
apple-touch-startup-image-1536x2008.png
apple-touch-startup-image-1496x2048.png
apple-touch-startup-image-768x1004.png
apple-touch-startup-image-748x1024.png
apple-touch-startup-image-640x1096.png
apple-touch-startup-image-640x920.png
apple-touch-startup-image-320x460.png
総オーバーヘッド
3KBの追加HTMLであるコメントを取り出す場合、1.5KBのスプラッシュスクリーンをサポートしない場合。HTMLコンテンツでGZIP圧縮を使用している場合（これは誰もが最近行っていることです）、すべてのプラットフォームをサポートするために要求ごとに約634バイトのオーバーヘッド、またはスプラッシュスクリーンなしの446バイトが残ります。私は個人的には、IOS、Android、Windowsデバイスをサポートする価値があると思いますが、それはあなたの選択です。
現在のWebアイコン/スプラッシュ画面/設定状況に関する補足
ベンダー固有のアイコン、スプラッシュ画面、およびWebブラウザーを制御する特別なタグやピン留めされたアイコンのこの状況は、ばかげています。完璧な世界では、すべてのサイズで見栄えがよく、ページのルートに配置できるfavicon.svgファイルをすべて使用します。執筆時点では、FireFoxのみがこれをサポートしています（CanIUse.comを参照）。
ただし、最近はアイコンだけが設定されているわけではなく、ベンダー固有の設定がいくつかあります（上記を参照）。ただし、favicon.svgファイルでほとんどの使用例をカバーできます。
更新
新しいAndroid / ChromeバージョンM39 +ファビコン/テーマオプションを含むように更新されました。興味深いことに、彼らはMicrosoftと同様のアプローチを行っていますが、XMLではなくJSONファイルを使用しています。