Permanent Identifiers for the Web

Secure, permanent URLs for your Web application that will stand the test of time.

The purpose of this website is to provide a secure, permanent URL re-direction service for Web applications. This service is run by the W3C Permanent Identifier Community Group.

Web applications that deal with Linked Data often need to specify and use URLs that are very stable. They utilize services such as this one to ensure that applications using their URLs will always be re-directed to a working website. This website operates like a switchboard, connecting requests for information with the true location of the information on the Web. The switchboard can be reconfigured to point to a new location if the old location stops working.

There are a growing group of organizations that have pledged responsibility to ensure the operation of this website. These organizations are: Digital Bazaar, 3 Round Stones, OpenLink Software, Applied Testing and Technology, Openspring, and Bosatsu Consulting. They are responsible for all administrative tasks associated with operating the service. The social contract between these organizations gives each of them full access to all information required to maintain and operate the website. The agreement is setup such that a number of these companies could fail, lose interest, or become unavailable for long periods of time without negatively affecting the operation of the site.

This website operates in HTTPS-only mode to ensure end-to-end security. This means that it may be used for Linked Data applications that require high levels of security such as those found in the financial, medical, and public infrastructure sectors.

All identifiers associated with this website are intended to be around for as long as the Web is around. This means decades, if not centuries. If the final destination for popular identifiers used by this service fail in such a way as to be a major inconvenience or danger to the Web, the community will mirror the information for the popular identifier and setup a working redirect to restore service to the rest of the Web.

If you would like to add or update a permanent identifier to the website, the preferred procedure is to perform the following steps:

  1. Fork the website on Github.
  2. Add or update a new redirect entry and commit your changes.
  3. Submit a pull request for your changes.

Please help out the maintainers of the service with the following:

You can also send a request to add a redirect to the mailing list. Make sure to include the URL that you want on, the URL that you want to redirect to, and the HTTP code that you want to use when redirecting. An administrator will then create the redirect for you.

There is not yet an official policy on identifier names. The current practice is to claim a top-level directory name and add project specific second level identifiers. For instance, Shared top-levels are also available such as There is not yet an official list or policy for reserved identifiers. However, the administrators may deny requests for identifiers that are too generic, could cause confusion, are inappropriate or offensive, or otherwise may be needed for future service expansion.

If you wish to engage the community in discussion about this service for your Web application, please send an e-mail to the mailing list.

The letters 'w3' in the domain name for this site stand for "World Wide Web". Other than hosting the software for the Permanent Identifier Community Group, the "World Wide Web Consortium" (W3C) is not involved in the support or management of this website in any way.