About LibCRC

LibCRC is an MIT licensed library written in C containing various checksum algorithms. These include the most common CRC implementations but also other checksums like the NMEA checksum used by marine equipment. Previously these routines could be downloaded from the site www.lammertbies.nl. Those sources have been merged with further unpublished developments and are now available as a full library. Also test routines and documentation have been enhanced to make the library easier to implement.


LibCRC is licensed under the MIT license. Therefore the library can be used in both open and closed source projects. Please consult the LICENSE file in the root of the source tree for more information about the licensing requirements.


The main repository for the LibCRC library can be found on Github. Please note that this is the development tree of the library so it is not guaranteed that the code is always stable. If you require production ready code, it is better to download one of the release source packages which can also be found at Github.

If you don't want to compile the sources yourself, downloading one of the pre-compiled library files from this site in the download section is also an option. Pre-compiled libraries are only available for the most common development environments though.


The best way to discuss problems with the library is by raising an issue in the Github repository at github.com/lammertb/libcrc/issues. The Error Detection and Correction Forum is now read only, but is still a valuable resource for previous discussions.

Online CRC Calculation

Although the CRC routine source files have moved away from www.lammertbies.nl, the online CRC calculator is still there. If you need to compute just a few CRC values, it may be easier to use that service than build an application based on LibCRC.

Lammert Bies