Frequently Asked Questions

These Frequently Asked Questions about the DOI System and DOI® names are not meant to take the place of the more detailed information available in the DOI Handbook. See also the Glossary of Terms, for definitions of related terms
If you have a question that you think should be added to this list, or a question is not satisfactorily answered, please feel free to contact us at

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1. How do I get a Digital Object Identifier (DOI)?

You must use a service offered by a DOI Registration Agency (RA). RAs collect metadata, assign DOI names, and offer other services such as reference linking or metadata lookup. See the list of RAs and contact the ones whose services best meet your needs. If you do not see an appropriate RA listed, consider developing a community to build the service you require (see the DOI Handbook for more information). You do not need to be a member of The DOI Foundation in order to work with an RA.

2. How much does it cost to get a DOI and use the DOI system?

The cost of registering new DOI names depends on the services you purchase. Contact a DOI Registration Agency to discuss your options. Each RA is different, and each is free to offer its own business model. For an example of the costs of a DOI service, see the DataCite fee model. Existing DOI names are, and will always be, free to resolve.

3. How do I become a member of the International DOI Foundation?

Members of the DOI Foundation are organizations (not usually individuals). Membership is open to any organization supporting the development of the DOI system that wishes to join our community of communities. If you are interested then please contact us

4. How do I become a Registration Agency?

Any organization that can represent a defined ‘community of interest’ for allocating DOI prefixes to DOI Registrants can apply to The DOI Foundation to become an agency. They may be existing businesses, or new organizations; they may be large or small. For more on this topic, see the DOI Handbook. If you are interested then please contact us

5. Where can I look up a DOI? Is there a list?

The DOI system does not provide a central search capability across all DOI names, but most web search engines will show DOI names in the results of a search by title, by name, or by topic or related terms. The reverse will also work; enter a DOI name and the search engine will show you what item that DOI was assigned to. However, this sort of query facility may also be offered by Registration Agencies or other services for DOI names in one defined area, as a value-added feature. These may be a paid for service or free to all users. For an example, see Crossref free DOI lookup.

6. How many DOI names are there, and who uses them?

Approximately 300 million DOIs have been assigned to date. The users come from almost every country in the world. There are around 500 DOI resolutions per second.

7. Can the DOI system use, or work with, existing identifier schemes?

Yes. See the DOI Handbook for more information.

8. What can a DOI name be assigned to?

It can be any entity — physical, digital or abstract — that you wish to identify, primarily for sharing with an interested user community or managing as intellectual property. DOIs are designed to be used by humans and their machines. The DOI is used in construction, entertainment and in scholarly research.

9. If I have assigned a DOI name and I make a change to my material, should I assign a new DOI?

The DOI Foundation does not have any rules on this. Individual RAs adopt appropriate rules for their community and application. As a general rule, if the change is substantial and/or it is necessary to identify both the original and the changed material, then it is wide to assign a new DOI name

10. Is the DOI system a standard?

Yes. The DOI system was created by The DOI Foundation and was adopted as International Standard ISO 26324 in 2012. The Foundation is the ISO 26324 Registration Authority. Compliance with the DOI Handbook ensures compliance with the ISO 26324 standard. The standard was updated in 2022.

11. What is a shortDOI?

A shortDOI® is a shortcut to a DOI name. It provides a function similar to URL shortening services. shortDOIs are not themselves DOI names.

12. How does the DOI system differ from the Handle System?

The DOI system implements the Handle System and adds to it some other features.

13. The DOI Foundation is a membership organization. Who are the members?

The activities of the Foundation are governed by its members, operating under a legal Charter and formal By-laws. Membership is open to all organizations with an interest in digital network publishing, content distribution, rights management, and related technologies. Send a request for information about joining

14. Does the DOI system use a Content Distribution Network?

Yes. To provide as good a service as possible, the resolver uses Cloudflare as a provider of authoritative DNS service and as a Content Distribution Network (CDN). If you believe our use of Cloudflare is interfering with an automatically generated resolution request, please send us an email for advice. Please see the Factsheet for more information.

Updated February 12, 2023