< meta > Elemental overview
The tag provides metadata about the HTML document. The metadata is not displayed on the page, but is readable for the machine. It can be used in browsers (how to display content or reload pages), search engines (keywords), or other Web services. --w3school
Required Attributes
Properties |
value |
Description |
Content |
Some text |
Define meta information related to the HTTP-EQUIV or Name property |
Optional properties
Properties |
value |
Description |
Http-equiv |
Content-type/expire/refresh/set-cookie |
Associate the Content property to the HTTP header. |
Name |
Author/description/keywords/generator/revised/others |
Associate the Content property to a name. |
Content |
Some text |
Defines the format used to translate content property values. |
SEO optimization
Reference documents
- page Keywords , each page should have a unique set of keywords that describe the content of the page.
Use descriptive and Representative keywords and phrases that people may search for and accurately describe the information provided on the page. Tag content is too short, the search engine may not think of the content as relevant. Additional tokens should not exceed 874 characters.
<meta name="keywords" content="your tags" />
- page Description , each page should have a no more than 150 characters and can accurately reflect the content of the page description tag.
<meta name="description" content="150 words" />
- search Engine Indexing method , Robotterms is a set of values separated by commas (,), usually have the following values: None,noindex,nofollow,all,index and follow. Make sure that the nofollow and Noindex property values are used correctly.
<meta name="robots" content="index,follow" /><!-- all:文件将被检索,且页面上的链接可以被查询; none:文件将不被检索,且页面上的链接不可以被查询; index:文件将被检索; follow:页面上的链接可以被查询; noindex:文件将不被检索; nofollow:页面上的链接不可以被查询。 -->
- page redirection and refresh : The number within the content represents the time (in seconds) that is refreshed after a few minutes. If the URL is added, it is redirected to the specified Web page (search engines can be automatically detected and easily punished by the engine as misleading).
<meta http-equiv="refresh" content="0;url=" />
<Metaname= "author" content= "author name"/> <!--definition Web page author--><< Span class= "Hljs-title" >meta name= "google" content=" Index,follow "/>< meta name= "Googlebot" content= "Index,follow"/><meta name=" verify " content= "Index,follow"/>
Mobile devices
- viewport: Can optimize the display of mobile browser. If it is not a responsive web site, do not use Initial-scale or disable scaling.
Most of the 4.7-5-inch devices have a viewport width of 360px;5.5 inch set to 400px;iphone6 set to 375px;ipone6 plus set to 414px.
<meta name="viewport" content="width=device-width, initial-scale=1.0,maximum-scale=1.0, user-scalable=no"/><!-- `width=device-width` 会导致 iPhone 5 添加到主屏后以 WebApp 全屏模式打开页面时出现黑边 -->
- Width: widths (values/device-width) (range from 200 to 10,000, default to 980 pixels)
- Height: Altitude (Value/device-height) (range from 223 to 10,000)
- Initial-scale: Initial zoom ratio (range from >0 to 10)
- Minimum-scale: The minimum scale to allow the user to zoom
- Maximum-scale: Allows the user to zoom to the maximum scale
- User-scalable: Whether the user can manually indent (no,yes)
- Minimal-ui: You can minimize the upper and lower status bar when the page loads. (deprecated)
Note that many people use initial-scale=1 to non-responsive websites, which makes the site render at 100% width, and the user needs to manually move the page or zoom. If you use User-scalable=no or maximum-scale=1 with initial-scale=1 at the same time, users will not be able to zoom in/out of the page to see all the content.
- WebApp Full Screen mode : Fake app, offline app.
<meta name="apple-mobile-web-app-capable" content="yes" /> <!-- 启用 WebApp 全屏模式 -->
- Hide Status bar/Set status bar color : Only takes effect when webapp full screen mode is turned on. The content value is default | Black | Black-translucent.
<meta name="apple-mobile-web-app-status-bar-style" content="black-translucent" />
- Title after adding to the main screen
<meta name="apple-mobile-web-app-title" content="标题">
- Ignore numbers automatically recognized as phone numbers
<meta content="telephone=no" name="format-detection" />
- Ignore recognition mailboxes
<meta content="email=no" name="format-detection" />
- Add Smart App banner Smart app Banner: Tell the browser the app that corresponds to this website and display the download Banner (for example) on the page. Reference documents
<meta name="apple-itunes-app" content="app-id=myAppStoreID, affiliate-data=myAffiliateData, app-argument=myURL">
- Other reference documents
<!--optimized for handheld devices, mainly for older browsers that do not recognize viewport, such as BlackBerry--and<MetaName="Handheldfriendly"Content="True" ><!--Microsoft's Vintage browser--<MetaName="Mobileoptimized"Content=">"<!--UC Force vertical screen--<MetaName="Screen-orientation"Content="Portrait" ><!--QQ Forced vertical screen--<MetaName="X5-orientation"Content="Portrait" ><!--UC Mandatory fullscreen--<MetaName="Full-screen"Content="Yes" ><!--QQ Mandatory fullscreen--<MetaName="X5-fullscreen"Content="true" ><!--UC App mode--<meta name= "Browsermode" content="Application" ><!--QQ App mode--<meta name="X5-page-mode" content="app" ><! --Windows Phone Click No Highlight-<meta name="msapplication-tap-highlight" content="No" >
Web related
<meta charset=‘utf-8‘ />
- Use the latest version of IE and Chrome first
<Metahttp-equiv="X-ua-compatible"Content="Ie=edge,chrome=1"/><!--about x-ua-compatible-->< Meta http-equiv= "x-ua-compatible" content= "ie=6" ><!-- Use IE6--><meta http-equiv=< Span class= "Hljs-value" > "x-ua-compatible" content= "IE=7" ><!--use IE7--><meta http-equiv= "x-ua-compatible" Content= "ie=8" ><!--use IE8-->
- Browser Kernel control : Many domestic browsers are dual-core (WebKit and Trident), WebKit kernel high-speed browsing, IE core-compatible Web pages and the old version of the site. Web sites that add Meta tags can control what kernel rendering the browser chooses. Reference documents
<meta name="renderer" content="webkit|ie-comp|ie-stand">
The default kernel mode for dual-core browsers is as follows:
1. Sogou high-speed browser, QQ browser: IE core (compatibility mode)
2.360 Speed Browser, roaming browser: WebKit kernel (fast mode)
- prevents browsers from accessing page content from the local computer's cache : This setting allows visitors to browse offline.
<meta http-equiv="Pragma" content="no-cache">
<meta name="msapplication-TileColor" content="#000"/> <!-- Windows 8 磁贴颜色 --><meta name="msapplication-TileImage" content="icon.png"/> <!-- Windows 8 磁贴图标 -->
- site adaptation : Mainly used for pc-mobile phone page of the corresponding relationship.
<meta name="mobile-agent"content="format=[wml|xhtml|html5]; url=url"><!--[wml|xhtml|html5]根据手机页的协议语言,选择其中一种;url="url" 后者代表当前PC页所对应的手机页URL,两者必须是一一对应关系。 -->
- transcoding declaration : Using Baidu to open the Web page may be transcoded (such as stickers), to avoid transcoding can add the following meta
<meta http-equiv= "Cache-control" content= "No-siteapp"/
<meta http-equiv= "Cache-control" content= "No-cache"/>
Cache-control header field
CACHE-CONTROL Specifies the caching mechanism that requests and responses follow. Setting Cache-control in a request message or response message does not modify the caching process in another message processing process. The cache directives for the request include No-cache, No-store, Max-age, Max-stale, Min-fresh, only-if-cached, and the instructions in the response message include public, private, No-cache, No-store, No-transform, Must-revalidate, Proxy-revalidate, Max-age. The instructions in each message mean the following
public indicates that the response can be cached by any buffer
private indicates that the entire or partial response message for an individual user cannot be shared cache processing. This allows the server to simply describe a partial response message for the user, which is not valid for another user's request
No-cache indicates that the request or response message cannot be cached
No-store is used to prevent important information from being inadvertently published. Sending in the request message will make the request and response messages do not use the cache.
Max-age indicates that the client can receive a response that is not longer than the specified time (in seconds)
Min-fresh indicates that the client can receive responses that are less than the current time plus the specified time
Max-stale indicates that the client can receive a response message that exceeds the timeout period. If you specify a value for the Max-stale message, the client can receive a response message that exceeds the specified value for the timeout period.
Common META Tags collation