Question about Using OFL font within firmware in commercial product

Hi !

I am currently working on a commercial electric device with small LCD panel (5 inch or under) and running an embedded system without a proper font system.

We plan on displaying text message using Noto Sans / Noto Sans CJK (Google Font). Due to the nature of our embedded system, we have to “convert” font to glyph data and use a subset of them - only characters need to be displayed are stored in code. It’s not a trivial work but we manage get it done - at least, from technical standpoint.

But to use it (protection under OFL license) legally and properly within our product, I know we have to follow the OFL terms, and here’s what got me confused.

Going through OFL FAQ, I would assume that it’s possible to use fonts licensed under OFL in an embedded system ( Question 1.10 & Question 1.11 from FAQ) - but with what prerequisites?

  1. Do we have to mention the RFN of fonts we are using ? (For example," This product use Open Source Fonts include: Noto Sans, Noto Sans CJK " )

  2. Do we have to have some sort of acknowledgement or legal info section, to display full content of LICENSE_OFL.txt ?

  3. Or, could we display a link to https :// scripts . sil . org / OFL instead of full content in this case? (Please keep it mind that user can’t connect to internet with this device, so it doesn’t function like an actual hyperlink from ordinary desktop computer or mobile phone / tablet. )

  4. Or, is it sufficient that we just display a link to a pages on our own website, where we present all information listed above (include open source fonts we are using, full content of LICENSE_OFL.txt, even actual link to Noto Sans / Noto Sans CJK’s original website in Google Fonts. Since it runs on actual computer / phone / tablet so hyperlink on it will work without problem)

  5. Or we don’t have to do anything above, just use it in our system? ( Most unlikely, I know )

It’s a bit difficult to find related info about OFL usage on embedded system as well as example I could referred to, so appreciate if anyone could answer these questions !

Best Regards,


Hello Sam,

It would be sufficient for you to place the copyright notice and link to the OFL somehow accessible to the user, as in:

“Fonts are derived from Noto Sans, Copyright 2018 The Noto Project Authors (, and licensed under the SIL Open Font License, Version 1.1 (”

The links won’t work from the device, but someone could type them into a browser and see more info. You would not need to put the entire license in the device - a link would be enough.

BTW, Noto Sans has no RFNs.

Hope that helps,

Victor Gaultney

1 Like

Hi Victor,

Thank you so much! I’m having more confidence about applying fonts with OFL in our embedded system! And this answer may benefits other people working on similar condition as well :wink:

Once again, many thanks!