The Apache 2.0 patent license grant, set out in Section 3 of the license, gives every recipient of the software a perpetual, worldwide, non-exclusive, royalty-free, irrevocable license to any patent claims a contributor holds that are necessarily infringed by the code they contributed. It closes a gap the earlier Apache 1.1 license left open, where a contributor could share code and still, in theory, sue users over the patented methods that code implemented.1The Apache Software Foundation. Apache-2.0 License History The grant comes with a retaliation clause that terminates your rights if you file patent litigation against the software, and that trade-off is the heart of how the license works.
What Rights the Grant Actually Gives You
Each contributor licenses you to make, use, sell, offer to sell, import, and otherwise transfer the software. The license is perpetual, so it does not expire. It is worldwide, so borders do not matter. It is royalty-free, so there is no fee. And it is irrevocable, with the one exception discussed further down.2Apache Software Foundation. Apache License, Version 2.0
Non-exclusive means the contributor keeps the ability to license the same patents to other people on different terms. That does not weaken your license; it just means you do not have exclusivity. For a commercial product built on open-source infrastructure, the combination of irrevocable and royalty-free is what provides real legal stability: a contributor cannot decide next year to start demanding royalties from you or seek an injunction over your prior reliance on the license.
One quiet feature of Section 3 catches lawyers off guard. The copyright grant in Section 2 explicitly allows sublicensing. The patent grant does not.3Apache Software Foundation. Apache License, Version 2.0 Instead, every downstream recipient gets their patent license directly from the original contributor. In ordinary distribution this is invisible, because anyone receiving Apache 2.0 code automatically receives the grant. It matters if you are structuring a more complex licensing arrangement on top.
What the Grant Does Not Cover
A contributor does not hand over their whole patent portfolio. The license reaches only patent claims that are “necessarily infringed” by the contribution itself, or by the combination of that contribution with the Work it was submitted to.2Apache Software Foundation. Apache License, Version 2.0 If running the contributed code inherently practices a patented method, that claim is licensed. If a claim only gets triggered by some unrelated use, or by a modification someone else makes later, it is not.
An example makes it concrete. A contributor who holds patents on a database indexing algorithm and a separate encryption technique licenses the indexing patent only if the code they contributed implements that indexing algorithm. The encryption patent stays untouched.
The grant also reaches only claims that are “licensable” by the contributor, meaning the contributor must actually have the authority to license them. If a contributor works for a company that owns the relevant patents, the individual alone cannot grant rights they do not control. This is one reason many projects use Contributor License Agreements to clarify patent ownership before code lands in the repository.4The Apache Software Foundation. Applying the Apache License, Version 2.0
What counts as a “Contribution” is defined broadly. It covers the original version of the Work and any later work of authorship intentionally submitted for inclusion by the copyright owner or an authorized representative. “Submitted” includes electronic, verbal, or written communications sent to the maintainers, including mailing list messages, commits, and issue tracker entries.5Software Package Data Exchange (SPDX). Apache License 2.0 Because that definition is so wide, the license carries a safety valve: a copyright owner can mark a communication “Not a Contribution” to keep it outside the grant entirely.
One more scope point worth understanding. The grant attaches to the contribution as submitted and to its combination with the Work at that time. If a downstream user later modifies the code in a way that triggers a different patent claim, that new claim is not covered by the original contributor’s grant. Modifications can introduce patent exposure the original license does not address.
The Retaliation Clause That Terminates the License
Section 3 ends with a termination trigger that is one of the most consequential provisions in any permissive open-source license. If you file patent litigation against any entity, including a cross-claim or counterclaim in a lawsuit, alleging that the Work or a Contribution within it constitutes direct or contributory patent infringement, your patent license under Apache 2.0 terminates as of the date you filed.3Apache Software Foundation. Apache License, Version 2.0
The breadth surprises people. It is not limited to offensive lawsuits. If someone sues you for something unrelated and you respond with a patent counterclaim alleging that the Apache-licensed software infringes your patent, your license terminates the same way.6Santa Clara High Technology Law Journal. A Promise Without a Remedy: The Supposed Incompatibility of the GPLv2 and Apache v2 Licenses There is no carve-out for defensive claims. So the strategic question a patent holder has to weigh is whether the potential lawsuit is worth losing the right to use the software.
Termination runs from the filing date, not retroactively. Your use before you filed is not converted into infringement. From the filing date forward, though, you need a separate license to keep using the software, and without one, continued use exposes you to patent infringement claims under federal law.7Office of the Law Revision Counsel. 35 USC 271 – Infringement of Patent
What Losing the License Can Cost
If you keep using the software after termination, a patent holder can pursue infringement damages. Under 35 USC 284, damages must be at least enough to compensate the patent holder, with a reasonable royalty as the floor, and courts can increase the award up to three times the assessed amount for willful infringement.8Office of the Law Revision Counsel. 35 USC 284 – Damages There is no fixed formula for the royalty. The Federal Circuit rejected the old “25 percent rule of thumb” as fundamentally flawed and inadmissible, so royalties are calculated case by case on the specific technology and market. For a company deeply dependent on an Apache-licensed project, the exposure from losing the patent license can be substantial.
Patent Grant vs. Copyright Grant
Sections 2 and 3 of the license share the same “perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable” language, and readers routinely conflate them. They are not the same.2Apache Software Foundation. Apache License, Version 2.0
The copyright grant covers reproduction, preparation of derivative works, public display, public performance, sublicensing, and distribution of the Work and Derivative Works. The patent grant covers making, using, selling, importing, and transferring the software, but only to the extent the activities would infringe claims necessarily infringed by the contribution. Copyright includes sublicensing; patent does not. Copyright reaches the Work and all Derivative Works; patent is scoped narrowly to the contribution.
Only the patent grant carries the retaliation termination trigger. The copyright grant has no equivalent. So a user who files patent litigation over the software can lose the patent license while keeping the copyright license, an odd legal position that is worth remembering the next time someone treats the two grants as interchangeable.
Trademarks Are Not Included
The patent grant, like the copyright grant, does not extend to trademarks. The license explicitly excludes permission to use the trade names, trademarks, service marks, or product names of any contributor.1The Apache Software Foundation. Apache-2.0 License History You can fork an Apache-licensed project and build whatever you want on the code, but you cannot use the original project’s logo on your product or use a contributor’s brand to imply endorsement. Any trademark use requires separate written permission.
GPL Compatibility Depends on the Version
If you are combining Apache 2.0 code with GPL-licensed code, the GPL version matters. The Free Software Foundation considers Apache 2.0 compatible with GPLv3, so Apache 2.0 code can be included in a GPLv3 project. The reverse is not permitted: GPLv3 code cannot be pulled into Apache projects, because the GPL’s copyleft would force the combined software to ship under GPLv3, conflicting with the Apache Software Foundation’s requirement that its projects be distributed under Apache 2.0.9The Apache Software Foundation. Apache License v2.0 and GPL Compatibility
GPLv2 is the harder case. The Free Software Foundation has never treated Apache 2.0 as compatible with GPLv2, pointing to the patent termination provision and indemnification clauses as restrictions the older GPL does not accommodate.9The Apache Software Foundation. Apache License v2.0 and GPL Compatibility If your project depends on GPLv2-only code, you cannot mix it with Apache 2.0 components without resolving the conflict, usually by getting the GPLv2 code relicensed or finding an alternative.