PNG Cyclic Redundancy Checksum

CRC, a C++ library which computes the PNG Cyclic Redundancy Checksum (CRC) for a string of bytes.

PNG is the Portable Network Graphics format. The PNG checksum algorithm is used as part of the encoding of a PNG file.


The computer code and data files made available on this web page are distributed under the GNU LGPL license.


CRC is available in a C++ version.

Related Data and Programs:


PNG, a data directory which contains examples of Portable Network Graphics (PNG) files, 2D graphics;


  1. World Wide Web Consortium,
    Portable Network Graphics (PNG) Specification,
    Second edition, 10 November 2003.

Source Code:

Last revised on 22 February 2020.