MIT vs GPL-3.0 License

MIT License compared with GNU General Public License v3.0: what each licence allows, and whether code under one can be used in a project under the other. Results are generated by the open-source license compatibility checker.

Quick Answer

Compatibility is directional, so both directions are answered separately (distributed software):

MIT code in a project licensed under GPL-3.0

Generally Compatible

Using MIT-licensed code in a project under GPL-3.0 is generally compatible in this scenario.

MIT code can generally be included in a project under GPL-3.0; the combined work is distributed under GPL-3.0 while the MIT notices for that code are retained.

GPL-3.0 code in a project licensed under MIT

Potential Conflict

Using GPL-3.0-licensed code in a project under MIT may conflict, depending on how the code is combined, distributed and licensed.

Using GPL-3.0 code in a project under MIT is one-directional: MIT code can go into a work under GPL-3.0, but a distributed work containing GPL-3.0 code must as a whole be licensed under GPL-3.0. Your own files may keep MIT, yet the project can no longer be distributed under MIT alone.

Key Differences

Copyleft: MIT: none; GPL-3.0: strong.
Source disclosure: MIT: not required; GPL-3.0: whole distributed work based on it.
Same licence for distributed changes: MIT: no; GPL-3.0: yes.
Mark modified files: MIT: no; GPL-3.0: yes.
Express patent licence: MIT: no; GPL-3.0: yes.
Patent termination clause: MIT: no; GPL-3.0: yes.

Comparison Table

	MIT	GPL-3.0
Type	Open source	Open source
OSI approved	Yes	Yes
Commercial use	Permitted	Permitted
Modification	Permitted	Permitted
Distribution	Permitted	Permitted
Copyleft	None	Strong
Network-use (SaaS) clause	No	No
Source disclosure	Not required	Whole distributed work based on it
Same licence for distributed changes	No	Yes
Attribution / notices	Yes	Yes
Mark modified files	No	Yes
Express patent licence	No	Yes
Patent termination clause	No	Yes
Trademark rights granted	Not addressed	Not addressed

Commercial Use

MIT: permitted.
GPL-3.0: permitted.

MIT code in a project licensed under GPL-3.0: MIT permits commercial use.
GPL-3.0 code in a project licensed under MIT: GPL-3.0 permits commercial use. Commercial use, including selling copies, is allowed; the copyleft conditions still apply to how the code is distributed.

Proprietary Software

MIT code in closed-source commercial software

Generally Compatible

Using MIT-licensed code in a proprietary project is generally compatible in this scenario.

MIT generally allows the code to be included in proprietary software without releasing your source code, provided its notices are kept.

GPL-3.0 code in closed-source commercial software

Likely Incompatible

Using GPL-3.0-licensed code in a proprietary project is likely incompatible in this scenario, as the licence terms are generally understood.

If a work based on GPL-3.0 code is distributed, the whole work must be licensed under GPL-3.0 with its complete source available. That is generally incompatible with distributing the project under proprietary terms.

MIT code in closed-source commercial software: MIT generally allows the code to be included in proprietary software without releasing your source code, provided its notices are kept.
GPL-3.0 code in closed-source commercial software: If a work based on GPL-3.0 code is distributed, the whole work must be licensed under GPL-3.0 with its complete source available. That is generally incompatible with distributing the project under proprietary terms.

SaaS

Network-use clause: MIT: no; GPL-3.0: no.

MIT code in a closed-source SaaS

Generally Compatible

Using MIT-licensed code in a proprietary project is generally compatible in this scenario.

MIT generally allows the code to be included in proprietary software without releasing your source code, provided its notices are kept.

GPL-3.0 code in a closed-source SaaS

Compatible With Conditions

Using GPL-3.0-licensed code in a proprietary project is generally possible if the listed conditions are met.

GPL-3.0 has no network-use clause: running GPL-3.0 code on your servers to provide a service, without distributing it, generally does not require releasing source. This depends on the code not being distributed.

MIT code in a closed-source SaaS: MIT has no network-use (SaaS) clause.
GPL-3.0 code in a closed-source SaaS: GPL-3.0 has no network-use clause: running GPL-3.0 code on your servers to provide a service, without distributing it, generally does not require releasing source. This depends on the code not being distributed.

Modification

MIT: permitted.
GPL-3.0: permitted; modified files must be marked.

Modifying MIT code used in closed-source software

Generally Compatible

Using MIT-licensed code in a proprietary project is generally compatible in this scenario.

MIT generally allows the code to be included in proprietary software without releasing your source code, provided its notices are kept.

Modifying GPL-3.0 code used in closed-source software

Likely Incompatible

Using GPL-3.0-licensed code in a proprietary project is likely incompatible in this scenario, as the licence terms are generally understood.

Modifying MIT code used in closed-source software: MIT permits modification.
Modifying GPL-3.0 code used in closed-source software: GPL-3.0 permits modification. GPL-3.0 requires modified files to carry notices stating that they were changed.

Distribution

MIT: permitted.
GPL-3.0: permitted.

MIT code in a project licensed under GPL-3.0: MIT permits distribution.
GPL-3.0 code in a project licensed under MIT: Using GPL-3.0 code in a project under MIT is one-directional: MIT code can go into a work under GPL-3.0, but a distributed work containing GPL-3.0 code must as a whole be licensed under GPL-3.0. Your own files may keep MIT, yet the project can no longer be distributed under MIT alone.

Copyleft

MIT: none copyleft.
GPL-3.0: strong copyleft.

MIT code in a project licensed under GPL-3.0: MIT code can generally be included in a project under GPL-3.0; the combined work is distributed under GPL-3.0 while the MIT notices for that code are retained.
GPL-3.0 code in a project licensed under MIT: Using GPL-3.0 code in a project under MIT is one-directional: MIT code can go into a work under GPL-3.0, but a distributed work containing GPL-3.0 code must as a whole be licensed under GPL-3.0. Your own files may keep MIT, yet the project can no longer be distributed under MIT alone.

Source Disclosure

MIT: not required.
GPL-3.0: whole distributed work based on it.

MIT code in a project licensed under GPL-3.0: MIT does not require you to publish source code.
GPL-3.0 code in a project licensed under MIT: Using GPL-3.0 code in a project under MIT is one-directional: MIT code can go into a work under GPL-3.0, but a distributed work containing GPL-3.0 code must as a whole be licensed under GPL-3.0. Your own files may keep MIT, yet the project can no longer be distributed under MIT alone.

Attribution

MIT: Include the copyright notice and permission notice in all copies or substantial portions.
GPL-3.0: License the whole conveyed work under GPL-3.0.
GPL-3.0: Provide Corresponding Source when conveying object code.
GPL-3.0: Keep copyright and licence notices and include the licence.
GPL-3.0: Mark modified versions with prominent notices of changes.
GPL-3.0: Provide Installation Information for User Products.

MIT code in a project licensed under GPL-3.0: MIT requires the copyright and licence notices to be kept with copies you distribute.
GPL-3.0 code in a project licensed under MIT: GPL-3.0 requires the copyright and licence notices to be kept with copies you distribute.

Patent Considerations

Express patent licence: MIT: no; GPL-3.0: yes.
Patent termination clause: MIT: no; GPL-3.0: yes.

MIT code in a project licensed under GPL-3.0: MIT contains no express patent licence. Any patent permission would depend on implied licence doctrines, which vary by jurisdiction.
GPL-3.0 code in a project licensed under MIT: GPL-3.0 includes an express patent licence from contributors. That patent licence terminates for anyone who initiates patent litigation alleging that the work infringes a patent.

Common Scenarios

Scenario	MIT code in a project licensed under GPL-3.0	GPL-3.0 code in a project licensed under MIT
Use as a dependency / library	Generally Compatible	Potential Conflict
Copy source code into the project	Generally Compatible	Potential Conflict
Modify the component	Generally Compatible	Potential Conflict
SaaS / network service (not distributed)	Generally Compatible	Compatible With Conditions
Internal / private use only	Generally Compatible	Generally Compatible
Resell the software	Generally Compatible	Potential Conflict
White-label / rebrand	Generally Compatible	Potential Conflict

FAQ

Can I use MIT code in a project licensed under GPL-3.0?

Using MIT-licensed code in a project under GPL-3.0 is generally compatible in this scenario. MIT code can generally be included in a project under GPL-3.0; the combined work is distributed under GPL-3.0 while the MIT notices for that code are retained.

Can I use GPL-3.0 code in a project licensed under MIT?

Using GPL-3.0-licensed code in a project under MIT may conflict, depending on how the code is combined, distributed and licensed. Using GPL-3.0 code in a project under MIT is one-directional: MIT code can go into a work under GPL-3.0, but a distributed work containing GPL-3.0 code must as a whole be licensed under GPL-3.0. Your own files may keep MIT, yet the project can no longer be distributed under MIT alone.

Can MIT-licensed code be used in closed-source commercial software?

Using MIT-licensed code in a proprietary project is generally compatible in this scenario. MIT generally allows the code to be included in proprietary software without releasing your source code, provided its notices are kept.

Can GPL-3.0-licensed code be used in closed-source commercial software?

Using GPL-3.0-licensed code in a proprietary project is likely incompatible in this scenario, as the licence terms are generally understood. If a work based on GPL-3.0 code is distributed, the whole work must be licensed under GPL-3.0 with its complete source available. That is generally incompatible with distributing the project under proprietary terms.

Do I have to publish my source code when I use MIT code?

MIT does not require you to publish source code.

Do I have to publish my source code when I use GPL-3.0 code?

Can I use MIT code in a closed-source SaaS?

Can I use GPL-3.0 code in a closed-source SaaS?

Using GPL-3.0-licensed code in a proprietary project is generally possible if the listed conditions are met. GPL-3.0 has no network-use clause: running GPL-3.0 code on your servers to provide a service, without distributing it, generally does not require releasing source. This depends on the code not being distributed.

Try the Interactive Checker

Change the scenario, say whether the code is modified, distributed or offered as SaaS, and see every rule that applies.

Check MIT in a GPL-3.0 project Check GPL-3.0 in a MIT project

Related Comparisons

Authoritative Sources

This tool provides general software licensing information and is not legal advice. License obligations may depend on how software components are combined, modified, distributed and used. For high-risk results, review the actual license text before relying on this result.