Document Encoding

UTF-8UTF-8

UTF-8 Usage Statistics

UTF-8 (8-bit UCS/Unicode Transformation Format) is a variable-length character encoding for Unicode. It is the preferred encoding for web pages.

Document Standards

HTML5 DocTypeHTML5 DocType

HTML5 DocType Usage Statistics

The DOCTYPE is a required preamble for HTML5 websites.

X-UA-CompatibleX-UA-Compatible

X-UA-Compatible Usage Statistics

Allows a website to define how a page is rendered in Internet Explorer 8, allowing a website to decide to use IE7 style rendering over IE8 rendering.

Cache ControlCache Control

Cache Control Usage Statistics

Cache Control setting on the page to provide caching performance gains.

JavascriptJavascript

Javascript Usage Statistics

JavaScript is a scripting language most often used for client-side web development.

Content Type OptionsContent Type Options

Content Type Options Usage Statistics

Used to disable MIME-sniffing for a particular HTTP response.

X-Frame-OptionsX-Frame-Options

X-Frame-Options Usage Statistics

The X-Frame-Options HTTP response header can be used to indicate whether or not a browser should be allowed to render a page in a frame or iframe. Sites can use this to avoid clickjacking attacks, by ensuring that their content is not embedded into other sites.

X-XSS-ProtectionX-XSS-Protection

X-XSS-Protection Usage Statistics

X-XSS-Protection is a HTTP header set by Internet Explorer 8+. This header lets domains toggle on and off the "XSS Filter" of IE8, which prevents some categories of XSS attacks.