Compare software

Image OptimizerOptiPNG
Free

Free and open source under the MIT licence.

 Free

Free and open source under the zlib licence.

Linux Windows, Command line
  • Lossless compression with identical pixels
  • Processes a whole folder at once
  • Lossless recompression of PNG files
  • Converts BMP, GIF, PNM and TIFF to optimized PNG
  • Only PNG and JPEG
  • Overwrites the original files in place
  • Command line only, no graphical interface
  • Lossless only, so savings are smaller than lossy tools
Downloadable app Downloadable app
Open source Open source
License: MIT License: Zlib
No account needed No account needed
Not stated if it works offline Works offline

Checked October 1, 2026

Checked October 2, 2026

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