Robots meta tag, data-nosnippet, and X-Robots-Tag specifications

Abstract

This document details how the page- and text-level settings can be used to adjust how Google presents your content in search results. You can specify page-level settings by including a meta tag on HTML pages or in an HTTP header. You can specify text-level settings with the data- nosnippet attribute on HTML elements within a page.

Using the robots meta tag

The robots meta tag lets you utilize a granular, page-specific approach to controlling how an individual page should be indexed and served to users in Google Search results. Place the robots meta tag in the <head> section of a given page, like this:

<!DOCTYPE html>
<html><head>
<meta name="robots" content="noindex" />
(…)
</head>
<body>(…)</body>
</html>

The robots meta tag in the above example instructs search engines not to show the page in search results. The value of the name attribute (robots) specifies that the directive applies to all crawlers. To address a specific crawler, replace the robots value of the name attribute with the name of the crawler that you are addressing. Specific crawlers are also known as user-agents (a crawler uses its user-agent to request a page.) Google's standard web crawler has the user-agent name Googlebot. To prevent only Googlebot from crawling your page, update the tag as follows:

<meta name="googlebot" content="noindex" />

This tag now instructs Google specifically not to show this page in its search results. Both the name and the content attributes are non-case sensitive.

Search engines may have different crawlers for different properties or purposes. See the complete list of Google's crawlers. For example, to show a page in Google's web search results, but not in Google News, use the following meta tag:

<meta name="googlebot-news" content="noindex" />

To specify multiple crawlers individually, use multiple robots meta tags:

<meta name="googlebot" content="noindex">
<meta name="googlebot-news" content="nosnippet">

Using the X-Robots-Tag HTTP header

The X-Robots-Tag can be used as an element of the HTTP header response for a given URL. Any directive that can be used in a robots meta tag can also be specified as an X-Robots-Tag. Here's an example of an HTTP response with an X-Robots-Tag instructing crawlers not to index a page:

HTTP/1.1 200 OK
Date: Tue, 25 May 2010 21:42:43 GMT
(…)
X-Robots-Tag: noindex
(…)

Multiple X-Robots-Tag headers can be combined within the HTTP response, or you can specify a comma-separated list of directives. Here's an example of an HTTP header response which has a noarchive X-Robots-Tag combined with an unavailable_after X-Robots-Tag.

HTTP/1.1 200 OK
Date: Tue, 25 May 2010 21:42:43 GMT
(…)
X-Robots-Tag: noarchive
X-Robots-Tag: unavailable_after: 25 Jun 2010 15:00:00 PST
(…)

The X-Robots-Tag may optionally specify a user-agent before the directives. For instance, the following set of X-Robots-Tag HTTP headers can be used to conditionally allow showing of a page in search results for different search engines:

HTTP/1.1 200 OK
Date: Tue, 25 May 2010 21:42:43 GMT
(…)
X-Robots-Tag: googlebot: nofollow
X-Robots-Tag: otherbot: noindex, nofollow
(…)

Directives specified without a user-agent are valid for all crawlers. The HTTP header, the user-agent name, and the specified values are not case sensitive.

Valid indexing & serving directives

The following directives can be used to control indexing and serving with the robots meta tag and the X-Robots-Tag. Each value represents a specific directive. The following table shows all the directives that Google honors and their meaning. Multiple directives may be combined in a comma-separated list. These directives are case- insensitive. Within search results, a snippet is a brief extract of text used to demonstrate the relevance of a document to a user's query.

Directives

all
There are no restrictions for indexing or serving. This directive is the default value and has no effect if explicitly listed.
noindex
Do not show this page in search results.
nofollow
Do not follow the links on this page.
none
Equivalent to noindex, nofollow.
noarchive
Do not show a cached link in search results.
nosnippet
Do not show a text snippet or video preview in the search results for this page. A static image thumbnail (if available) may still be visible, when it results in a better user-experience. This applies to all forms of search results (at Google: web search, Google Images, Discover).
max-snippet:[number]

Use a maximum of [number] characters as a textual snippet for this search result. (Note that a URL may appear as multiple search results within a search results page.) This does not affect image or video previews. This applies to all forms of search results (such as Google web search, Google Images, Discover, Assistant). However, this limit does not apply in cases where a publisher has separately granted permission for use of content. For instance, if the publisher supplies content in the form of in-page structured data or has a license agreement with Google, this setting does not interrupt those more specific permitted uses. This directive is ignored if no parseable [number] is specified.

Special values:

  • 0: No snippet is to be shown. Equivalent to nosnippet.
  • -1: There is no snippet length limit.
  • max-snippet is effective starting late October, 2019.

    Example:

    <meta name="robots" content="max-snippet:20">
    max-image-preview:[setting]

    Set the maximum size of an image preview for this page in a search results.

    Accepted setting values:

  • none: No image preview is to be shown.
  • standard: A default image preview may be shown.
  • large: A larger image preview, up to the width of the viewport, may be shown.
  • This applies to all forms of search results (such as Google web search, Google Images, Discover, Assistant). However, this limit does not apply in cases where a publisher has separately granted permission for use of content. For instance, if the publisher supplies content in the form of in-page structured data (such as AMP and canonical versions of an article) or has a license agreement with Google, this setting will not interrupt those more specific permitted uses.

    Publishers who do not want Google to use larger thumbnail images when their AMP pages and canonical version of an article are shown in search or Discover should specify a max-image-preview value of standard or none.

    max-image-preview is effective starting late October, 2019.

    Example:

    <meta name="robots" content="max-image-preview:standard">
    max-video-preview:[number]

    Use a maximum of [number] seconds as a video snippet for videos on this page in search results.

    Other supported values:

  • 0: At most, a static image may be used, in accordance to the max-image-preview setting.
  • -1: There is no limit.
  • This applies to all forms of search results (at Google: web search, Google Images, Google Videos, Discover, Assistant). This directive is ignored if no parseable [number] is specified.

    max-video-preview is effective starting late October, 2019.

    Example:

    <meta name="robots" content="max-video-preview:-1">
    notranslate
    Do not offer translation of this page in search results.
    noimageindex
    Do not index images on this page.
    unavailable_after: [date/time]

    Do not show this page in search results after the specified date/time. The date/time must be specified in a widely adopted format including, but not limited to RFC 822, RFC 850, and ISO 8601. The directive is ignored if no valid [date/time] is specified. By default there is no expiration date for content.

    Example:

    <meta name="robots" content="unavailable_after: Sunday, 01-Sep-24 01:00:00 PDT">

    Handling combined indexing and serving directives

    You can create a multi-directive instruction by combining robots meta tag directives with commas. Here is an example of a robots meta tag that instructs web crawlers to not index the page and to not crawl any of the links on the page:

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

    Here is an example that limits the text snippet to 20 characters, and allows a large image preview:

    <meta name="robots" content="max-snippet:20, max-image-preview:large">
    

    For situations where multiple crawlers are specified along with different directives, the search engine will use the sum of the negative directives. For example:

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

    The page containing these meta tags will be interpreted as having a noindex, nofollow directive when crawled by Googlebot.

    Using the data-nosnippet HTML attribute

    The data-nosnippet attribute is effective starting later in 2019.

    You can designate textual parts of a HTML page not to be used as a snippet. This can be done on a HTML-element level with the data-nosnippet HTML attribute on span, div, and section elements. The data-nosnippet is considered a boolean attribute, it is valid with or without a value. To ensure machine- readability, the HTML section must be valid HTML and all appropriate tags must be closed accordingly.

    Examples:

    <p>This text can be shown in a snippet
     <span data-nosnippet>and this part would not be shown</span>.</p>
    
    <div data-nosnippet>not in snippet</div>
    <div data-nosnippet="true">also not in snippet</div>
    
    <div data-nosnippet>some text</html>
    <!-- unclosed "div" will include all content afterwards -->
    
    <mytag data-nosnippet>some text</mytag>
    <!-- NOT VALID: not a span, div, or section -->
    

    Google typically renders pages in order to index them, however rendering is not guaranteed. Because of this, extraction of data-nosnippet may happen both before and after rendering. To avoid uncertainty from rendering, do not add or remove the data-nosnippet attribute of existing nodes through JavaScript. When adding DOM elements through JavaScript, include the data-nosnippet attribute as necessary when initially adding the element to the page's DOM. If custom elements are used, wrap or render them with div, span, or section elements if you need to use data- nosnippet.

    Using structured data

    Robots meta tags govern the amount of content that Google extracts automatically from web pages for display as search results. But many publishers also use schema.org structured data to make specific information available for search presentation. Robots meta tag limitations don't affect the use of that structured data, with the exception of article.description and the description values for structured data specified for other creative works. To specify the maximum length of a preview based on these description values, use the max-snippet robots meta tag. For example, recipe structured data on a page is eligible for inclusion in the recipe carousel, even if the text preview would otherwise be limited. You can limit the length of a text preview with max-snippet, but that robots meta tag doesn't apply when the information is provided using structured data for rich results.

    To manage the use of structured data for your web pages, modify the structured data types and values themselves, adding or removing information in order to provide only the data you want to make available. Also note that structured data remains usable for search results when declared within a data-nosnippet element.

    Practical implementation of X-Robots-Tag

    You can add the X-Robots-Tag to a site's HTTP responses through the configuration files of your site's web server software. For example, on Apache-based web servers you can use .htaccess and httpd.conf files. The benefit of using an X-Robots-Tag with HTTP responses is that you can specify crawling directives that are applied globally across a site. The support of regular expressions allows a high level of flexibility.

    For example, to add a noindex, nofollow X-Robots-Tag to the HTTP response for all .PDF files across an entire site, add the following snippet to the site's root .htaccess file or httpd.conf file on Apache, or the site's .conf file on NGINX

    Apache:

    <Files ~ "\.pdf$">
      Header set X-Robots-Tag "noindex, nofollow"
    </Files>
    

    NGINX:

    location ~* \.pdf$ {
      add_header X-Robots-Tag "noindex, nofollow";
    }
    

    You can use the X-Robots-Tag for non-HTML files like image files where the usage of robots meta tags in HTML is not possible. Here's an example of adding a noindex X-Robots-Tag directive for images files (.png, .jpeg, .jpg, .gif) across an entire site:

    Apache:

    <Files ~ "\.(png|jpe?g|gif)$">
      Header set X-Robots-Tag "noindex"
    </Files>
    

    NGINX:

    location ~* \.(png|jpe?g|gif)$ {
      add_header X-Robots-Tag "noindex";
    }
    

    Combining crawling with indexing / serving directives

    Robots meta tags and X-Robots-Tag HTTP headers are discovered when a URL is crawled. If a page is disallowed from crawling through the robots.txt file, then any information about indexing or serving directives will not be found and will therefore be ignored. If indexing or serving directives must be followed, the URLs containing those directives cannot be disallowed from crawling.