Nanopb - protocol buffers with small code size

Nanopb is a plain-C implementation of Google's Protocol Buffers data format. It is targeted at 32 bit microcontrollers, but is also fit for other embedded systems with tight (<10 kB ROM, <1 kB RAM) memory constraints.


Latest stable releases

The development happens in GitHub repository (browse repository):

        git clone


Bugs can be reported on the GitHub issue tracker.

There is a discussion forum on Google Groups. Please ask any questions there.

Commercial support is available from devEmbedded.



The zlib license:

Copyright (c) 2011 Petteri Aimonen <jpa at>

This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software.

Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.

Used by

Here are a few users of nanopb who have posted public attribution notices:

Similar projects

There are a few other projects aiming to provide C protobuf libraries:

There are also a few small size C++ implementations: