Keyfill Licence Agreement

Last updated 12 November 2026. By downloading, installing or using Keyfill you agree to this licence. If you don't agree, don't install or use it.

1. The licence

Keyfill, including its updates, documentation and the example shows that come with it (together, "Keyfill"), is free. Keyfill ("we") grants you a free, non-exclusive, non-transferable licence to install and use Keyfill on any number of computers, for any purpose, commercial productions included. Keyfill is licensed, not sold: we keep all rights not given here.

2. What you may not do

  1. Sell, rent or lease Keyfill, or charge for it as it is.
  2. Modify, adapt or make derivative works of Keyfill, or reverse engineer, decompile or disassemble it, except where the law allows it in spite of this.
  3. Remove, obscure or alter any copyright, trademark or other notice in or on Keyfill or the software inside it.
  4. Use Keyfill for anything unlawful.

3. What you make is yours

Your shows, graphics, data and output belong to you. We claim no rights in them, and Keyfill doesn't send them to us.

4. Open-source software inside

Keyfill includes open-source software, among it FFmpeg under the GNU Lesser General Public License 2.1, each under its own licence, listed in full in Help › Acknowledgements. Where this licence and one of those disagree about that software, its own licence applies; nothing here limits the rights it gives you.

5. NDI®

Keyfill sends video over the network with NDI®. NDI® is a registered trademark of Vizrt NDI AB (ndi.video). The NDI runtime inside Keyfill and the NDI software development kit (the "NDI SDK"), and the NDI products, are copyright © NDI, Inc. (Vizrt NDI AB) and its licensors, all rights reserved. Keyfill is not a product of Vizrt NDI AB, and is not sponsored or endorsed by it. In addition to the terms above:

  1. You may not modify the NDI SDK, the NDI runtime or any NDI product, or any part of them.
  2. You may not reverse engineer, disassemble or recompile the NDI SDK, the NDI runtime or any NDI product, or any part of them, or any protocol they use, whether sent or received over a network or used inside or outside the machine, physical or virtual, they run on; nor attempt to.
  3. You may not circumvent any technical limitation in the NDI SDK, the NDI runtime or any NDI product, or any part of them.
  4. You may not remove, obscure or alter any proprietary notice or label in or on the NDI SDK, the NDI runtime or any NDI product, or any part of them.
  5. Vizrt NDI AB and each of its licensors disclaim all warranties, express or implied, for the NDI SDK, the NDI runtime and the NDI products, and, as far as the law allows, all liability for any damages, direct, indirect, incidental or consequential, arising from the use of Keyfill or of anything it's bundled with.
  6. You'll comply fully with all relevant export laws and regulations of the United States, so that Keyfill and the NDI parts of it are not exported, directly or indirectly, in violation of United States law.
  7. If you use Keyfill to develop a product of your own that uses NDI, that product must comply with the NDI SDK licence (ndi.link/ndisdk_license), including keeping current and complete NDI compatibility, and its own end-user licence must include the terms of this section.

6. Other trademarks

Blackmagic Design, DeckLink, UltraStudio and ATEM are trademarks of Blackmagic Design. Other names are their owners' trademarks. Their use in Keyfill only says what it works with; it doesn't suggest that their owners sponsor or endorse Keyfill.

7. Updates

Keyfill checks for newer versions and installs them when you quit. Each update is under this licence, or under the licence that comes with it.

8. No warranty

Keyfill is provided "as is" and "as available", without warranty of any kind, express or implied, including merchantability, fitness for a particular purpose, non-infringement and that it will run without error or interruption. You use it at your own risk; for anything going to air, test it first and keep a backup.

9. Limit of liability

As far as the law allows, neither we nor our licensors (Vizrt NDI AB among them) are liable for any damages, direct, indirect, incidental, special or consequential, including lost broadcasts, airtime, revenue, data or goodwill, arising from the use of or the inability to use Keyfill, even if told they were possible. Where the law doesn't allow liability to be excluded, it's limited to the least the law allows.

10. Export

You'll comply with all export control and sanctions laws that apply to Keyfill, including those of the United States, and won't export or re-export it to any country, organisation or person they prohibit.

11. Ending

This licence lasts until it ends. It ends at once, without notice, if you break its terms; you must then stop using Keyfill and remove it. You may end it at any time by removing Keyfill. Sections 3, 5 (its disclaimers), 8, 9 and 12 last after it ends.

12. General

This is the whole agreement between you and us about Keyfill. If any part of it can't be enforced, the rest still applies. Not enforcing a term isn't giving it up. We may change this licence for future versions; the licence that comes with a version is the one that applies to it.