What the license is
Apache License 2.0 is one of the most common open-source licenses. It is published by the Apache Software Foundation and is used for software and, increasingly, for AI models. When a model is released under it, you get broad rights to use it without asking permission or paying a fee.
What it lets you do
- Use it commercially. You can build a paid product on it.
- Modify it. You can change it, including fine-tuning a model for your own data.
- Redistribute it. You can share the original or your modified version.
- Run it anywhere. You can host it yourself, on your own hardware or in the cloud.
What it asks of you
The conditions are light. You must include a copy of the license and any notices, and say clearly which files you changed. You may not use the original authors' names or trademarks to promote your product without permission.
It also includes an express patent grant. Contributors give you a license to any patents their contribution covers, and that license can end if you sue them over those patents. Many companies prefer Apache 2.0 for this reason.
Why it matters for AI models
Not every model labeled "open" is as open as this. Some release model weights under custom licenses that restrict commercial use, cap the number of users, or limit certain fields. An open-weight model under Apache 2.0 has none of those limits, so you can plan a business around it.
Two cautions:
- Weights are not everything. A license on the weights does not mean the training data or training code is public. Apache 2.0 says what you may do with what is released, nothing more.
- Check each release. A model family can use different licenses for different sizes or versions. Read the license file in the repository you actually download from.
Example
A team wants to run a coding model inside its own network so no code leaves the building. A model under Apache 2.0 allows that, along with adapting it with LoRA and shipping the result in a product. A model under a restrictive custom license may not.
The license governs the use of open-weight models, and it is separate from whether the model is any good. Test it on your own tasks with evals before relying on it. Running it yourself also means paying for the compute it needs.