PNG(5) File Formats Manual PNG(5)

# [NAME](#NAME)

png - Portable Network Graphics (PNG) format

# [DESCRIPTION](#DESCRIPTION)

PNG (Portable Network Graphics) is an extensible file format for the lossless, portable, well-compressed storage of raster images. PNG provides a patent-free replacement for GIF, and can also replace many common uses of TIFF. Indexed-color, grayscale, and truecolor images are supported, plus an optional alpha channel. Sample depths range from 1 to 16 bits.

PNG is designed to work well in online viewing applications, such as the World Wide Web, so it is fully streamable with a progressive display option. PNG is robust, providing both full file integrity checking and fast, simple detection of common transmission errors. Also, PNG can store color space data for improved color matching on heterogeneous platforms.

# [SEE ALSO](#SEE_ALSO)

[**libpng**(3)](/man/os/libpng/libpng.3), **zlib**(3), **deflate**(5), and **zlib**(5)

Portable Network Graphics (PNG) Specification (Third Edition):

W3C Recommendation 24 June 2025  
https://www.w3.org/TR/2025/REC-png-3-20250624/

Portable Network Graphics (PNG) Specification (Second Edition):

ISO/IEC 15948:2004(E)  
https://www.iso.org/standard/29581.html

W3C Recommendation 10 November 2003  
https://www.w3.org/TR/2003/REC-PNG-20031110/

Portable Network Graphics (PNG) Specification Version 1.2:

Published by the PNG Development Group on 14 July 1999  
https://www.libpng.org/pub/png/spec/1.2/

Portable Network Graphics (PNG) Specification Version 1.1:

Published by the PNG Development Group on 15 February 1999  
https://www.libpng.org/pub/png/spec/1.1/

Portable Network Graphics (PNG) Specification Version 1.0:

IETF RFC 2083, March 1997  
https://www.ietf.org/rfc/rfc2083.txt

W3C Recommendation 1 October 1996  
https://www.w3.org/TR/REC-png-961001

# [AUTHORS](#AUTHORS)

This man page: Glenn Randers-Pehrson, Cosmin Truta, Chris Lilley.

PNG Specification (Third Edition): Chris Blume et al.

PNG Specification (Second Edition): David Duce et al.

PNG Specification Version 1.2: Glenn Randers-Pehrson et al.

PNG Specification Version 1.1: Glenn Randers-Pehrson et al.

PNG Specification Version 1.0: Thomas Boutell et al.

September 28, 2026

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Document: png(5) from libpng 1.6.59-r0 (Chainguard OS)
Source: https://github.com/pnggroup/libpng