Open Data Licenses
Open government data is published under various licenses that define how the data can be used, shared, and redistributed. Understanding these licenses is essential for building applications, combining datasets from multiple sources, and ensuring legal compliance.
License Comparison
| License | Attribution Required | Share-Alike | Commercial Use | Derivative Works | Used By |
|---|---|---|---|---|---|
| CC0 | No | No | Yes | Yes | World Bank |
| CC-BY 4.0 | Yes (credit to source, link to license, indicate changes) | No | Yes | Yes | Australia (data.gov.au) |
| CC-BY-SA 4.0 | Yes | Yes (same or compatible license) | Yes | Yes (under same license) | OpenStreetMap (transitioned from ODbL for some layers) |
| ODbL 1.0 | Yes | Yes (for derivative databases) | Yes | Yes (database must remain ODbL; produced works can use any license) | OpenStreetMap (primary database) |
| OGL v3.0 | Yes (acknowledge source, provide link to license where possible) | No | Yes | Yes | UK government (data.gov.uk) |
| OGL-Canada | Yes (acknowledge Government of Canada as source) | No | Yes | Yes | Government of Canada (open.canada.ca) |
| Public Domain | No (courtesy attribution appreciated but not legally required) | No | Yes | Yes | All US federal agencies (Census |
License Details
CC0 1.0 (Public Domain Dedication)
View full textWaives all copyright and related rights. Data can be used for any purpose without attribution or restriction. The most permissive open data license.
Creative Commons Attribution 4.0 (CC-BY 4.0)
View full textPermits any use (including commercial) as long as appropriate credit is given to the original source. The most widely used open data license requiring attribution.
Creative Commons Attribution-ShareAlike 4.0 (CC-BY-SA 4.0)
View full textRequires attribution and that derivative works be shared under the same or compatible license. Creates a copyleft obligation on derived datasets.
Open Data Commons Open Database License (ODbL 1.0)
View full textDatabase-specific copyleft license. Requires attribution, share-alike for derivative databases, and that any technical restrictions (DRM) be accompanied by an open version.
UK Open Government Licence v3.0 (OGL)
View full textUK government license for Crown copyright data. Permits commercial and non-commercial use with attribution. Designed to be compatible with CC-BY 4.0.
Open Government Licence - Canada
View full textCanadian federal government open data license. Similar to UK OGL. Permits reproduction, distribution, and commercial use with attribution to the Government of Canada.
US Public Domain
View full textWorks produced by the US federal government are not subject to copyright protection under 17 U.S.C. Section 105. No license is needed; data is in the public domain by law.
Practical License Guidance
Combining datasets from multiple sources
When merging data from different portals, the most restrictive license applies to the combined dataset. CC0 and public domain data can be combined with anything. CC-BY data combined with ODbL data must comply with both attribution and ODbL share-alike requirements.
When no license is specified
If a government dataset has no explicit license, do not assume it is public domain (unless it is US federal data, which is public domain by law). Contact the publishing agency to clarify terms before commercial use.
Attribution best practices
Even when attribution is not legally required (CC0, US public domain), providing source attribution is good practice. It builds trust, helps data provenance tracking, and acknowledges the effort of data publishers.