Robots Are Our Friends

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Revision as of 12:37, 17 November 2012 by Edsu (Talk | contribs) (Typical Reasons for not allowing Robots)

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For a variety of reasons cultural heritage organizations often have robots.txt documents that restrict what web crawlers (aka robots) can see on a website. This is a bad thing because it means that the content that libraries, archives and museums are putting online becomes virtually invisible to search engines like Google, Bing, Yahoo, is less likely to be shared in social media sites like Facebook, Twitter, Flickr, Pinterest and stands less of a chance of being used in educational sites like Wikipedia. The Robots Are Our Friends campaign aims to help promote an understanding of the role that robots.txt plays in determining the footprint our cultural heritage collections have on the Web.


Typical Reasons for not allowing Robots

  • While indexing a dynamic site, robots can put an extra strain on the server, causing a slow response, or in some cases, pegging the CPU at 100%.
  • Some content is intentionally shielded from search engines to help shape how a websites resources are presented in search results. For example, if an organization has put a lot of PDFs online and doesn't want those to turn up in search results.



Several major search engines support the [ crawl delay directive, which you can put in your robots.txt file. This directive lets you tell web crawlers the minimum delay to wait between two successive requests.

User-agent: *
Crawl-delay: 3


  1. Log in to Google Webmaster Tools
  2. Select your site
  3. In the left-hand side, select Configuration and then Settings
  4. Under Crawl rate select Limit Google's maximum crawl rate
  5. Use the slider to adjust the amount of requests per second/number of seconds between requests
  6. Hit Save

Note: This may take a day or two to go into effect and it only lasts for 90 days, at which point it will revert back to Google selecting the crawl rate.


  1. Log in to Bing Webmaster Tools
  2. Select your site
  3. In the left-hand side, select Configure My Site and then Crawl Control
  4. Use the 2D chart to change the crawl rate for specific times of day. Or you can use the drop-down menu to move crawl activity to off-peak hours of traffic.

Note: Directives in robots.txt will override this setting (e.g. Setting Crawl-delay)


"Sitemaps are an easy way for webmasters to inform search engines about pages on their sites that are available for crawling. In its simplest form, a Sitemap is an XML file that lists URLs for a site along with additional metadata about each URL (when it was last updated, how often it usually changes, and how important it is, relative to other URLs in the site) so that search engines can more intelligently crawl the site." --

The full specification is available at

Creating a sitemap

List of sitemap generators including Drupal and Wordpress.

Some library software specific sitemap generators exist:

Telling Search Engine about your sitemap

Sitemaps can be added into your robots.txt, or submitted directly to Google Webmaster Tools or Bing.


add a line like this to your robots.txt file:

Sitemap: http://yourdomain.tld/path/to/sitemap.xml


  1. Log in to Google Webmaster Tools
  2. Select your site
  3. In the left-hand side, select Optimization and then Sitemaps
  4. Click Add/Test Sitemap
  5. Enter the path to your sitemap on your server and click Submit Sitemap

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