License chooser · dependency conflict checker
Pick the right license — and catch the GPL footgun.
Answer four plain-English questions to get the right open-source license with its full text and SPDX
id. Then paste your package.json or requirements.txt and licensepicker checks every
dependency’s license for conflicts — all in your browser.
1 · Pick a license
Should others be able to keep their changes closed?
Require keeping your copyright notice?
Do you want an explicit patent grant?
Short, permissive, the most popular OSS license. Do almost anything; just keep the notice.
MIT License Copyright (c) 2026 Your Name Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. 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 OR COPYRIGHT HOLDERS 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.
2 · Check your dependencies
Paste a package.json or requirements.txt. Each dependency’s license is fetched from the public registry and checked against your project license.
Informational guidance only — not legal advice. License compatibility, especially around copyleft, can depend on how code is combined and distributed. Confirm important decisions with a qualified professional.
Why licensepicker
choosealicense.com helps you pick. licensepicker also checks what you’re already pulling in:
- Four-question chooser — maps your intent to MIT, Apache-2.0, MPL, LGPL, GPL, AGPL or the Unlicense.
- Dependency compatibility — resolves each dep’s license from npm/PyPI and flags GPL-in-MIT and similar conflicts.
- Real SPDX output — copy a ready LICENSE file and the canonical SPDX id for your manifest.
- Private — manifests are parsed in your browser; only public registry lookups leave your machine.
Frequently asked questions
Is licensepicker free?
Yes — completely free, no account, no sign-up. It runs entirely in your browser.
Is this legal advice?
No. licensepicker gives informational guidance to help you choose a license and spot obvious dependency conflicts. License compatibility — especially around copyleft — can depend on how code is combined and distributed, so confirm important decisions with a qualified professional.
How does the dependency check work?
Paste a package.json or requirements.txt. For each dependency, licensepicker fetches the declared license from the public npm or PyPI registry (CORS, no API key), classifies it, and checks it against the project license you chose. Your manifest is never uploaded to us — the registry calls go straight from your browser.
Why does a GPL dependency “conflict” with my MIT project?
A strong-copyleft (GPL) dependency generally requires the entire combined work to be released under the GPL. If your project is MIT, Apache, or proprietary, distributing it with a GPL dependency is a conflict unless you relicense the whole project. AGPL goes further and is triggered even by network/SaaS use.
What is the difference between MIT, Apache-2.0 and BSD?
All three are permissive: anyone can use your code, even commercially, as long as they keep your notice. MIT and BSD are short and simple; Apache-2.0 adds an explicit patent grant and a NOTICE requirement, which companies often prefer. BSD-3-Clause additionally forbids using your name to endorse derivatives.
When should I pick GPL, LGPL, MPL or AGPL?
MPL-2.0 keeps only the files you change open (you can still combine it with closed code). LGPL is for libraries you want usable in closed apps via dynamic linking. GPL keeps the whole distributed work open. AGPL extends that to software run as a network service.
Which weekday numbering or version suffix do you use?
licensepicker recommends the current GNU versions (e.g. GPL-3.0, AGPL-3.0) and outputs canonical SPDX identifiers so they’re machine-readable in your package metadata.