pngquant – command-line utility and a library for lossy compression of PNG images

pngquant is a command-line utility and a library for lossy compression of PNG images.

The conversion reduces file sizes significantly (often as much as 70%) and preserves full alpha transparency. Generated images are compatible with all web browsers and operating systems.

pngquant is free and open source software.

Features include:

  • High-quality palette generation using a combination of vector quantization algorithms.
  • Advanced quantization algorithm with support for gamma correction and premultiplied alpha
  • Unique adaptive dithering algorithm that adds less noise to images than the standard Floyd-Steinberg.
  • Configurable quality level.
  • Automatically finds required number of colors and can skip images which can’t be converted with the desired quality
  • Easy to integrate with shell scripts, GUIs and server-side software. It’s based on a portable libimagequant library.
  • Fast mode for real-time processing/large numbers of images.
  • Multicore support (via OpenMP) and Intel SSE optimizations.

Website: pngquant.org
Support: GitHub Code Repository
Developer: Jef Poskanzer and Greg Roelofs
License: GNU General Public License Version 3

pngquant is written in C and Rust. Learn C with our recommended free books and free tutorials. Learn Rust with our recommended free books and free tutorials.

Return to Command-Line Image Compression Tools Home Page


Popular series
Linux for StartersNew to Linux? Read our Linux for Starters series. We start right at the basics and teach you everything you need to know to get started with Linux.
Free and Open Source SoftwareThe largest compilation of the best free and open source software in the universe. Each article is supplied with a legendary ratings chart helping you make informed decisions.
Linux ReviewsHundreds of in-depth reviews offering our unbiased and expert opinion on software. We offer helpful and impartial information.
Alternatives to GoogleAlternatives to Google's Products and Services examines your options to migrate from the Google ecosystem with open source Linux alternatives.
MicrosoftAlternatives to Microsoft's Products and Services recommends open source Linux software.
AdobeAlternatives to Adobe Cloud looks at free and open source alternatives to products available from Adobe Cloud's subscription service.
AppleAlternatives to Apple recommends free and open source alternatives to Apple's proprietary world.
CorelAlternatives to Corel surveys alternatives to Corel's range of graphics processing products and other software applications.
DockerGetting Started with Docker helps you master Docker, a set of platform as a service products that delivers software in packages called containers.
Linux System ToolsEssential Linux system tools focuses on small, indispensable utilities, useful for system administrators as well as regular users.
Linux ProductivityLinux utilities to maximise your productivity. Small, indispensable tools, useful for anyone running a Linux machine.
Home Computer EmulatorsHome computers became commonplace in the 1980s. Emulate home computers including the Commodore 64, Amiga, Atari ST, ZX81, Amstrad CPC, and ZX Spectrum.
Now and ThenNow and Then examines how promising open source software fared over the years. It can be a bumpy ride.
Linux at HomeLinux at Home looks at a range of home activities where Linux can play its part, making the most of our time at home, keeping active and engaged.
Linux CandyLinux Candy reveals the lighter side of Linux. Have some fun and escape from the daily drudgery.
Best Free Android AppsBest Free Android Apps. We showcase free Android apps that are definitely worth downloading. There's a strict eligibility criteria for inclusion in this series.
Programming BooksThese best free books accelerate your learning of every programming language. Learn a new language today!
Programming TutorialsThese free tutorials offer the perfect tonic to our free programming books series.
Stars and StripesStars and Stripes is an occasional series looking at the impact of Linux in the USA.
Share this article