From the Super Mario Wiki

PNG Monster is a program that compresses PNG files to the smallest filesize as possible without changing how the image looks like. It uses a variety of compression methods that attempt to compress the file down. To download it, go to this page.

(NOTE: The files are packaged in a .rar archive file. If you have no idea how to open the file, I recommend downloading 7-Zip in order to open it.)

After downloading the file, open it, and you will see a folder named "PNG Monster". Pull the whole folder out, and place it in a desired location. Open the unpackaged folder, and click on the executable file that looks like a Cookie Monster (the blue furry guy that has a cookie on it's hand).

Upon opening the file - a small window will pop up. By there, you will see the following things on the window (from top to bottom):

  • Source Directory – A line of text is automatically written; informing you where you put the "PNG Monster" folder. If placed in the Desktop, it should say "Desktop/PNG Monster" in the box or some other variation.
  • A checkbox with the text "Loop (very slow)" – If checkmarked, it will enable the program to compress the image(s) to the max limit. Therefore, it might take longer to finish compressing the image(s) depending on the size of the image, and the amount of color palettes.
  • A button that says "Run!" – If clicked, the program will use the directory line from "Source Directory", and proceed to search for any PNG images within the folder you assigned the program to.
  • Log – A large empty box. If the "Run!" button is clicked, the box will show the number of files "fed" to the program (which includes PNGs, and non-PNG files), and tells you the name of the file the program is currently compressing (or "digesting"). After the process is done, and all the PNG files are compressed, it will inform you how many PNG files the program compressed, number of bytes before compression, number of bytes after compression, and the percentage of compression (lower number means the image is widely compressed).

When done, the PNG files should be very well compressed and ready to go.

(NOTE: I recommend that you backup your PNG files you're going to compress them incase something wrong happens.)


  • When I ran the program, a small window opens and says "Run-time error '6': Overflow". What does this mean?
  • It basically means the program didn't find any PNG files at all, thus aborting the program.
  • Is there a way to revert the compressed images back to normal?
  • Nope, once the process is done, it can't be reverted. The program is designed to replace an uncompressed file, with a new compressed file.
  • Who created this program?
  • A user named Spodi has created this program in his spare time of coding. For more info about him, visit his userpage.
  • The image I compressed has changed it's color. Did I do something wrong?
  • Not at all, the program is designed to rearrange and remove unnecessary info when altering images, including: gamma correction (a term for how the image is displayed by upping it's brightness or lowering it down - most browsers unfortunately display PNG images incorrectly if this is used), interlace (a method that lets the image load in a cool way when it appears), and other stuff internet browsers don't actually read.