There are many resources available on the net that are in the public domain, and therefore freely usable and unrestricted for Appropedia content. However, there are resources that Appropedia considers to be in the public domain and others not, or usable with restrictions.

There are also many copyrighted assets whose licensing terms are elastic enough that they can also be used.

Appropedia's Public Domain Search (PDS) is a custom search engine which searches sites that contain mostly or completely public domain content. The majority of these sites are from the US federal government; others are added when we are made aware of them. As far as possible, other content is excluded.

Please check your results before assuming they're public domain. As a rule of thumb, US federal government (and only federal) sites are public domain unless there is a copyright or permissions notice that declares otherwise. This includes federal departments and agencies. Other levels of government will be copyright restricted.

Beware of state, territory and local government sites that slip through our net - these are not public domain. This includes sites ending in state names and abbreviations such as and, territory names such as, and county names such as, but other sites have less obvious urls such as There are hundreds or more of such sites.[1] Use caution.

Public domain images: After searching, click the "Image" tab above the results.

Why is this needed?[edit | edit source]

There was no effective public domain search before this, and we aren't aware of any that have been built since. (If you are aware of any, please leave a message on the talk page.}

There are ways to search for open licensed content which has been tagged with a Creative Commons "mark" (or which uses a CC0 public domain "mark" from Creative Commons). Click "Advanced search" in your Google search and choose the relevant permissions. Or go to Creative Commons' search page - there are Google, Flickr and other search options. However, these won't give you public domain results.

(Note that if you want material compatible with Appropedia or Wikipedia and you're using one of these Creative Commons search engines, you need to select "free to use, share or modify, even commercially". (Although Appropedia is not-for-profit, our license allows commercial use, so we can't use content with a non-commercial license.) Also note that these searches, like the PDS, aren't perfect - some of the results won't match the permissions you specified.

Appropedia's "Public Domain Search" on this page mostly searches sites that don't use a Creative Commons mark, and can't be found in Creative Commons searches.

Public domain is also different from other open content (i.e. CC-by and CC-by-sa).

Status (under development)[edit | edit source]

This search is functioning but is not properly refined. It returns useful results, but a significant number of non-public domain hits come up.

Seeking Law/IP Intern[edit | edit source]

Appropedia is looking for a law/IP intern, someone interested in this area, to help refine this Public Domain Search, based primarily on federal US government sources. If you are interested, please leave a message here. (User:Chriswaterguy is overseeing this project.)

Source[edit | edit source]

Note that all data use to create these searches is "open source" - see below for links and details.

Give feedback[edit | edit source]

If you know of any other true public domain sites, or find sites with the Public Domain Search which shouldn't be there, or other good public domain search engines, please let us know.

Disclaimer[edit | edit source]

NOTICE: Results are *mostly* public domain - but please double-check the content licensing before copying the content. Some pages (especially US state and local government that haven't been excluded yet) are not public domain, and others are not clearly marked - see US federal government websites and public domain for more information.

Porting public domain content[edit | edit source]

The main reason for creating and maintaining this custom search engine is to find and port good quality public domain content to Appropedia. If you are helping with this:

  • Search for your topic using the Appropedia Public Domain Search. Find content (e.g. projects, general topic information, how-tos) that would be
  • Make sure that the content really is public domain (look for a copyright notice, or "Web policies" or "Permissions"...)
    • If you can't find an explicit public domain notice, please ask on the talk page. You could also contact the website to ask.
    • If you find material that is actually copyright or somehow not suitable, please tell us on the talk page. This helps us to improve the search engine.
  • Port the content. The easiest way is to use WikEd. (See also Appropedia:Porting HTML to wiki - page needs updating.)
  • Use the {{pd source}} template notice at the bottom of the page.

Notes[edit | edit source]

  1. This search will never be perfect - there are many, many domains ending in .gov, and new domains are created each year. Some of these are federal; many of them are not and need to be excluded. We haven't caught them all yet.

See also[edit | edit source]

FA info icon.svg Angle down icon.svg Page data
Authors Chris Watkins, lzhlzh
License CC-BY-SA-3.0
Language English (en)
Translations Chinese, Russian, Portuguese, Thai, Spanish, Dutch, German, Japanese, Thai, Croatian
Related 15 subpages, 59 pages link here
Aliases Public Domain Test Search, Public Domain Beta Search, APDS, Public domain search engine, Public domain search, PD search engine, Appropedia's Public Domain Search, PDS
Impact 20,904 page views
Created November 18, 2007 by Chris Watkins
Modified June 9, 2023 by Felipe Schenone
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