The Unlicense
PermissiveSPDX identifier:
UnlicenseOSI ✓Data updated Sep 26, 2026In plain words
Dedicates the work to the public domain where possible, with a permissive fallback. No attribution is required.
Analogy: Leaving a book on a park bench with no name inside: anyone may take it.
Pros
- + No conditions at all
- + Easy to combine with anything
Cons
- - Public-domain dedication is not recognized in every country
- - Some companies avoid it for legal uncertainty
Well-known projects using it
5 well-known projects in our map use this license.
Permissions
- Commercial use
- Modification
- Distribution
- Private use
Conditions
Limitations
- No liability
- No warranty
Extreme scenarios · Code licenses
- A1AllowedA cloud vendor sells your project as a managed service
- A2AllowedSomeone forks it and distributes a closed-source competitor
- A3AllowedEmbedded in a closed-source SaaS backend (not distributed)
- A4AllowedLinked into a closed-source app or firmware and distributed
- A5Not addressedSomeone promotes a modified version with your name or trademark
- A6AllowedSomeone sells unmodified copies
- B1Not addressedA user sues you for patent infringement and keeps using the code
- B2Not addressedA contributor asserts patents on their contributed code
- B3Not addressedA cross-border dispute: governing law and venue
- C1AllowedYou later relicense or sell commercial licenses (contributors signed no CLA)
- C2AllowedYour code is merged into a GPL-3.0 project
- C3Blocked by licenseYou use a GPL-3.0 dependency and still ship under this license
- C4AllowedThe project is abandoned and someone forks it to continue
- C5Blocked by licenseYou want to block only big companies or competitors
- C6Not addressedKey code was written by an employee and the employer objects
- D1AllowedSomeone removes copyright or attribution notices
- D2AllowedSomeone modifies files without marking the changes
- D3AllowedInternal modification, no distribution and no external service
- D4AllowedUsed for military, surveillance or other uses you object to
- D5Not addressedUsed by a sanctioned entity
- D6Not addressedYour code is used to train an AI model
Worst-case radar
- 1Stops free-riding0
- 2Stops closed forks0
- 3Patent protection0
- 4Adoption friction0
- 5Hard to relicense0
Computed from the scenario matrix. Higher means more of that property, not "better".
Compare with…
Official text
Only the official text is legally binding. We do not translate license texts.
https://spdx.org/licenses/Unlicense.html
The Unlicense
This is free and unencumbered software released into the public domain.
Anyone is free to copy, modify, publish, use, compile, sell, or distribute this software, either in source code form or as a compiled binary, for any purpose, commercial or non-commercial, and by any means.
In jurisdictions that recognize copyright laws, the author or authors of this software dedicate any and all copyright interest in the software to the public domain. We make this dedication for the benefit of the public at large and to the detriment of our heirs and
successors. We intend this dedication to be an overt act of relinquishment in perpetuity of all present and future rights to this software under copyright law.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
For more information, please refer to <http://unlicense.org/>