Sign up ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I am searching for a software that will allow me to reduce the number of colors for PNG-24 transparent (as in photoshop) files. Photoshop doesn't allow me any control over the amount of colors the PNG is saved, having this kind of software/plugin would be great.

share|improve this question

migrated from Aug 8 '11 at 6:54

This question came from our site for professional and enthusiast programmers.

... i'm afraid you might be out of luck on this one. If you're thinking in terms of reducing the size of the file by limiting colors that won't happen. I think there are some ways / utilities to optimize png sizes, but color reduction 'gif-style' isn't one of them. – vector Aug 7 '11 at 21:34

2 Answers 2

You could use ImageMagick's convert application with the -color flag.

i.e: convert something.png -color 256

share|improve this answer
Thanks, but is their anything like a visual GUI instead of command line? – Idan Shechter Aug 7 '11 at 21:45
You could use the gimp which is a bit more geeky than Photoshop. But many would argue that their UI is pretty ugly. – John Mitchell Aug 15 '11 at 0:29

There are two tools:

  • pngquant which creates 256-color PNGs with alpha channel. That greatly reduces file sizes (60-70%). In latest versions it may have better quality and smaller file size than Photoshop's Save For Web (even for images without alpha).

  • mediancut posterizer reduces number of unique colors in 24/32-bit PNG files. This can reduce file sizes by 20-30%, and again is smarter than posterizing colors in Photoshop as it also posterizes alpha channel and is smarter about selecting posterization levels.

Both of those programs have a GUI: ImageAlpha.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.